What Is SEO? Search Engine Optimization Best Practices

Written by Miriam Ellis. Updated November 7, 2024.

SEO stands for search engine optimization. SEO practitioners optimize websites, webpages, and content to rank higher in search engines like Google. SEO is a set of practices designed to improve the appearance, positioning, and usefulness of multiple types of content in organic search results. This content can include web pages, video media, images, local business listings, and other assets.

Because organic search is the top method by which people discover and access online content, utilizing SEO best practices, including on-page optimization, is essential for ensuring that the digital content you publish can be found and chosen by the public, increasing your website’s organic traffic. On-page optimization helps improve search rankings and enhances user experience, which is crucial for maintaining high engagement and reducing bounce rates.

Brief history of SEO

Search Engine Optimization (SEO) has a rich and fascinating history that spans over two decades. The concept of SEO emerged in the mid-1990s, coinciding with the launch of the first search engines. These early search engines used simple algorithms to rank websites based on their content and relevance, marking the beginning of SEO as we know it.

In the late 1990s and early 2000s, SEO became a popular marketing strategy as businesses realized the importance of having a strong online presence. During this period, SEO techniques were relatively straightforward, focusing on keyword stuffing, meta tags, and link building. However, as search engines evolved and became more sophisticated, SEO techniques had to adapt.

A significant shift occurred in 2005 when Google introduced its Panda algorithm, targeting low-quality content and keyword stuffing. This update marked a new era in SEO, emphasizing the creation of high-quality, relevant content. In 2011, Google refined its approach with the Penguin algorithm, targeting link spam and manipulative link-building tactics. This update reinforced the importance of earning natural links through valuable content.

Today, SEO is a complex and multifaceted field that requires a deep understanding of search engine algorithms, user behavior, and content marketing. With the rise of voice search, artificial intelligence, and machine learning, SEO continues to evolve, adapting to new technologies and trends. Staying updated with these changes is crucial for maintaining a strong online presence and achieving long-term success in search engine rankings.

To learn how SEO works, it’s important to have a basic understanding of how search engines work. Search engines use crawlers (also known as spiders or bots) to gather information across the internet to populate their extensive databases, called “indexes.” Crawlers begin from a known webpage and then follow links from that page to other pages.

For example, suppose a page Google already indexed on Patagonia.com on the topic of used clothing features internal links to further pages for used jackets, hiking boots, and flannel shirts. In that case, Google can crawl to those pages via the links provided. Meanwhile, suppose Patagonia’s main used clothing page links to an article on TheGuardian.com about the negative impacts of fast fashion. In that case, Google can crawl from Patagonia to the news article via the link, thereby discovering that content and potentially indexing it.

The content of the discovered page and the context of the links the crawler followed from Patagonia to The Guardian help Google understand what the page is about and how it is relevant to all other pages within its index.

Suppose you are the journalist who wrote The Guardian article on fast fashion. In that case, the fact that a used outdoor clothing section of a large brand is linked to your piece indicates to Google that there might be a relationship between the problems of fast fashion and the potential solution of buying used clothing instead of new clothing. These semantic relationships go far towards helping Google determine which results to show for each query they receive from the searching public.

Search engines’ success as businesses depends on the public finding search engine results relevant to their needs. The more links a search engine like Google finds pointing from a particular type of content to a specific resource, the more confident it becomes that the linked-to resource is relevant to certain search queries. The search engine then determines that this resource deserves to be ranked highly when people make those queries.

There are three main categories of SEO: on-page SEO, off-page SEO, and technical SEO. All of these combine to help search engines discover, crawl, index, understand, and rank your content. This article will cover each of these topics. On-page optimization is crucial as it involves improving a website to enhance user experience and search rankings.

Algorithm updates and their impact

Search engine algorithms are constantly evolving to improve the quality and relevance of search results. These updates can have a significant impact on website rankings and traffic. Here are some of the most notable algorithm updates and their impact:

• Panda (2011): This update targeted low-quality content and keyword stuffing. Websites with thin or duplicate content saw a significant drop in rankings, pushing SEO practitioners to focus on creating high-quality, original content.
• Penguin (2011): Penguin aimed at link spam and manipulative link-building tactics. Websites with unnatural link profiles experienced a substantial drop in rankings, highlighting the importance of earning natural, high-quality backlinks.
• Hummingbird (2013): This update improved search results for long-tail keywords and natural language queries. It allowed Google to understand the context and intent behind queries better, benefiting websites with high-quality, relevant content.
• RankBrain (2015): Introduced machine learning to improve search results. RankBrain helps Google process and understand complex queries, rewarding websites with high-quality content and strong user engagement.
• BERT (2018): BERT enhanced Google’s understanding of natural language and context. This update improved search results for conversational queries, benefiting websites with well-written, contextually relevant content.
• Helpful Content Update (HCU) (2022): This update aimed to reward websites that provide valuable and informative content to users. It focused on demoting sites with content primarily created for search engine rankings rather than user benefit. The HCU emphasized the importance of creating people-first content that genuinely helps users, encouraging site owners to prioritize quality and relevance in their content strategies.

These algorithm updates underscore the importance of creating high-quality, relevant content and earning natural links. Staying informed about these changes and adapting your SEO strategy is essential for maintaining and improving your search engine rankings.

Search Engine Marketing and its role

Search Engine Marketing (SEM) is a form of digital marketing that involves promoting a website through paid advertising on search engines. SEM plays a crucial role in driving traffic and generating leads for businesses. Here are some key aspects of SEM:

• Paid Advertising: SEM involves creating and publishing paid ads on search engines like Google Ads. These ads appear at the top of search engine results pages (SERPs), providing immediate visibility to potential customers.
• Keyword Targeting: SEM targets specific keywords and phrases to reach relevant audiences. Businesses can ensure their ads appear in front of the right people by bidding on keywords that potential customers will likely use.
• Ad Copy and Landing Pages: Creating compelling ad copy and optimized landing pages is essential for driving conversions. Persuasive ad copy captures attention, while well-designed landing pages encourage visitors to take desired actions, such as purchasing or filling out a form.
• Budgeting and Bidding: SEM involves setting budgets and bidding on ad placements to ensure maximum return on investment (ROI). By carefully managing budgets and bids, businesses can control advertising costs and achieve marketing goals.

SEM is an essential complement to SEO, as it allows businesses to reach a wider audience and drive traffic to their website. By combining SEO and SEM, companies can create a powerful online marketing strategy that drives traffic, generates leads, and increases conversions.

A significant reason that SEO matters is because it helps online publishers appear within the results displayed by search engines. Search engines like Google and Bing each have their own methods of surfacing and formatting the content they display when a user enters a query into a search box, like this:

In response to a query like this, a search engine like Google can return a wide variety of results. Let's look at and label some of the different types of results here:

1. Traditional Organic Results

Google's most familiar results are the traditional organic results, which consist of links to website pages ranked in a particular order based on Google's algorithms. Search engine algorithms are a set of formulae used to determine the relevance of possible results to a user's query. In the past, Google commonly returned a page of 10 organic results for each query. Still, this number can vary widely, and the results will differ depending on whether the searcher uses a desktop computer, mobile phone, or other device. Traditional organic results look like this, with each entry having a title, description, link to the source, and other features like dates and additional links:

Bing's traditional organic results look and function similarly to Google's:

2. SERP Features

Beyond the traditional organic results, search engines can surface a variety of other displays that can be categorized under the umbrella term “SERP features.” There are many kinds of SERP features including but not limited to:

• Local pack results
• Google Business Profiles
• Knowledge panels
• Sitelinks
• Featured snippets
• Image packs and image carousels
• Video packs
• People Also Ask features
• Related searches
• Additional SERP features for news results, hotel and travel results, shopping, FAQs, job listings, and more.

Local pack results display a list of local businesses for some queries:

Google Business Profiles feature a single local business for some queries:

Knowledge panels feature information about organizations, people, and places for some queries:

Sitelinks are links to additional pages within a website that can also appear as part of that site's organic listing if the individual pages are strong enough or the search engine believes the individual pages are especially relevant to the user's query, like this example of an organic listing for a retailer including links to its pages for women's wear, men's wear, used clothing and more:

There are at least four main types of results called "featured snippets," including carousels, lists, paragraphs, and tables. Videos and rarer double-featured snippets are related features. To display featured snippets, Google pulls content from web pages to summarize right within the SERPs, linking it to the information's sources.

Image packs and image carousels that link to their sources:

Video packs that link to their sources:

“People also ask” features summarize and link to further information based on queries that relate to the user's original query:

“Related searches” features link to further sets of SERPs and can prompt users to expand their query to access related information:

Additional SERP features include news results, hotel and travel results, shopping, FAQs, job listings, and more. SEO is crucial because it influences what search engines surface for these results and features.
SEO doesn't influence any SERP component paid for by an advertiser. Paid search engine results can include ads stemming from the Google Ads program, like this example with its “sponsored” label:

Local business lead generation ads stemming from Google's Local Services Ads program, which are returned for some queries:

Any time a result is labeled “sponsored,” you'll know it is a paid ad placement and not influenced by your SEO efforts. However, nearly all of the other types of results search engines display are highly impacted by your optimization strategy.

Finally, it's important to know that both Google and Bing are currently in the early stages of offering Artificial Intelligence-based content to searchers, as explored by Tom Capper on the Moz Blog. The degree to which SEO can impact AI content is, as yet, unknown. For example, it's clear that SEO is having some impact on Google's Search Generative Experience (SGE) experiments because the content found in traditional local packs is being used to some extent in SGE responses to local queries, like this:

Currently, there is no precise strategy for seeking inclusion in offerings like Google's Bard or New Bing Chat. Over time, if these products become popular with the public, an SEO will study AI results and identify methods for building a presence within these novel formats and likely competing against them for visibility in the evolving SERPs.

While every SEO campaign can have unique goals, most online publishers are united in wanting to achieve some or all of the five following results from their investment in optimization:

1. More visibility in the SERPs

Most Google users stay within the first page of Google's results to find an answer to their query, and 75% will click on either the first or second result on the page. Because of this behavior, one primary goal of SEO is to rank more highly in the results for more searches. The more visible your content is, the better its chances of being found and chosen by the public.

At this stage in your learning, it's important for you to know that website owners shouldn't pursue the myth of #1 search engine rankings. Entities like Google will show different results to different users based on the location of their devices and even minor differences in the language of their queries. A better goal than being #1 is to be highly visible to your focus audience for your most important searches across multiple SERP styles and features.

2. More traffic to your website and other assets

When searchers reach your site via clicking on the organic SERPs, this is known as “traffic.” Whether the click-through rate (CTR) to your website pages from the SERPs impacts organic rankings in Google is a matter of ongoing controversy and debate in the SEO industry. Bing confirms that they use CTR and bounce rate (how quickly people leave your webpage after landing) as ranking factors. However, though the precise details of search engine algorithms remain secret, it stands to reason that SEO work aims to bring more traffic from the SERPs to your online assets.

3. Better quality traffic to your website and other assets

While winning a slew of traffic from the SERPs may, at first, sound like a dream come true to any site owner, it will typically only impact basic business goals if this traffic converts into sales or other key actions. For example, an independently owned doughnut shop in San Francisco might achieve first-page rankings in Google for sourdough doughnuts. It might go viral on social media for a funny or unusual marketing campaign and make it into mainstream news. It might receive national or even international traffic from these rankings and efforts. Still, when its product is only actually available to be purchased by customers in its city, most of this traffic will not convert to sales. It may only nominally support the viability of the company.

Because of this, a better goal than hoping for lots of traffic to your digital assets is to use SEO to strategize how to win the most qualified traffic for what you offer because this will typically have the highest conversion rate. High-quality organic traffic depends on search engines determining that your content is highly relevant for the queries you discover are most likely to result in conversions, whether your conversions are defined as sales, filling out forms, phone calls, leads, or even just customers spending more time on your website. You can access further learning on measuring traffic quality in this blog post tutorial by Adriana Stern.

4. Greater intelligibility to the public

One of the best things you can do in learning about SEO is to understand it as a form of customer service. Google rewards content that is useful to the public. Their 2022 Helpful Content algorithm update primarily focused on how they reward sites that publish helpful content to searchers. For decades, Google has urged site owners to create content for people rather than for search engines.

SEO can help your site be more intelligible, discoverable, and usable to potential visitors. Optimization influences both what your content looks like when shown within the SERPs and what it looks and behaves like when searchers click through to your digital assets. Providing good service and a great user experience to the public is one of the most practical reasons to invest in SEO.

5. Greater intelligibility to search engines

For search engines to feature and reward your content so that you can earn the visibility, traffic, and conversions you need, your website and other assets need to be intelligible to the crawlers/spiders/bots that entities like Google and Bing use to crawl and index digital content. This is achieved by multiple SEO efforts that can be broken down into:

• On-page SEO, which chiefly consists of how you optimize specific elements of a website page so that its contents are relevant and clear
• Technical SEO chiefly consists of managing the technical backend of your website so that search engines can effectively crawl, index, and understand it.
• Off-page SEO, which chiefly consists of how you earn links, citations, notice, and press from third parties, thereby building up the authority of your digital assets

These three areas of SEO work to ensure that search engines can match your content to their perceived intent of searchers' queries. The better search engines understand your content, the better your chances of achieving high, broad, and highly-converting rankings. Next, we'll look into each of these three concepts more deeply.

Optimizing your site generally involves three key focus areas: On-page, off-page, and technical SEO.

On-page SEO is the practice of optimizing your website content so search engines and humans can easily digest it. On-page optimization is critical because it improves a website to enhance user experience and search rankings. Technical SEO is any sufficient technical action undertaken to improve search results, usually through making your site function efficiently. Off-page SEO involves actions taken outside of your website to impact your rankings.

Together, they combine to create a solid foundation to enable you to reach your target audience.

Investing in SEO includes engaging in customer, market, and keyword research so that your content reflects the language real people use to search for whatever your website offers. The findings of your study can then be incorporated into your on-page optimization of multiple elements of your website and its pages, including but not limited to the following:

• Domain names
• Page URLs
• Page titles
• Headers
• Alt text
• Images
• Videos
• Navigational
• Meta description tags
• Internal links
• Sitemaps
• The main body text of each page

Read: The Beginner’s Guide to SEO for a complete tutorial on on-page SEO.

To ensure that your website can be properly indexed and crawled by search engines and properly used by people, technical SEO includes, but is not limited to, management of all of the following elements:

• Analytics setup
• Site crawling
• Indexing status
• Robots.txt status
• Canonicalization
• Internal link architecture design and management
• Coding
• Mobile-friendliness
• Cross-browser rendering
• Page status codes
• Image compression
• Core web Vitals status
• Page load/speed optimization
• Structured data
• JavaScript frameworks/rendering/pre-rendering
• Hreflang
• De-indexing
• Migrations

For a complete tutorial on technical SEO, read The Professional's Guide to SEO, and you'll also enjoy this popular web Developer's SEO Cheat Sheet.

To ensure that your digital assets achieve maximum visibility in the search engines, meet your goals for relevant traffic, and deliver the conversions you seek, off-page SEO can be defined as a practice for bringing attention to your content. Your options for pursuing this include, but aren't limited to:

• Earning links and citations from high-quality third-party sites via the merit of your content
• Managing link disavowal
• Proactively building links and citations from high-quality third-party sites via outreach to those publications.
• Engaging in a variety of forms of online promotion, including social media marketing, being featured as a guest on third-party blogs, podcasts, and vlogs
• Traditional PR, including writing press releases and building relationships with influencers
• For local businesses, creating local business profiles and building local unstructured citations

For a complete tutorial on off-page SEO, read Off-Page SEO. If you are optimizing a local business website, read The Essential Local SEO Strategy Guide.

The above factors influence how search engines understand and rank your website pages.

Over the past few decades, SEO professionals have made many ongoing efforts to identify as many of Google's proprietary organic rankings factors as possible and to organize them in the order by which they appear to influence rankings. The same has been done for search engines like Bing, and for some years, Moz conducted a major organic ranking factors survey and a local search ranking factors survey. A list of such factors could include, but not be limited to:

• On-page factors
• User behavior factors
• Link factors
• Core update factors
• Local guidelines factors
• Spam factors

There are also the elements known as Google's E-E-A-T factors, which, while not considered traditional, are direct ranking factors by many SEOs. These are principles that Google instructs its quality raters to evaluate when measuring search engine results quality. E-E-A-T factors can be defined as:  

• Experience — Is published content based on the author's first-hand experience? For example, if someone writes a restaurant review, did they demonstrably visit the place and try the food? Or, if an influencer recommends a shampoo brand, did they actually use it on their own hair?
• Expertise — Is published content created by someone who has become skilled in the subject they are covering? Does the author have degrees, licenses, or accreditations for your money-or-your-life (YMYL) topics like medical information or financial advice? Has the author accrued practical, everyday expertise through demonstrable experience for other categories of data, like do-it-yourself home repairs?
• Authoritativeness — Do third parties recognize the expertise of a source? Do established authoritative sites and people link to and cite the content in question, as in the case of a well-known food critic linking to their choice of the best Thai restaurant in Seattle, recognizing its expertise in this field.?
• Trustworthiness — Is content Factual and accurate? Are websites and transactions secure and built on the principles of good user experience (UX)? Is contact information accessible and accurate, are policies accessible and appropriate, and does public sentiment (like reviews) indicate that a business is above board and legitimate? Google calls trustworthiness the most important of all the E-A-T factors.

The problem inherent in trying to set in stone a list of factors that definitely have the most influence on organic rankings is that the SERPs have become so diverse.

If your organization sells shoes, your SEO and marketing efforts will need to be different than those undertaken by a hotel, an online gaming platform, an architectural firm, or a software developer. The SERPs will not only contain different components for each relevant query but may also be somewhat or completely different for each searcher based on their location; meanwhile, what the public needs and how it behaves may differ depending on the search intent.

As the myth of #1 search engine ranking faded into the past, the logic of realizing that one size simply doesn't fit all in SEO ranking factors may have contributed to us seeing fewer surveys these days trying to assign impact to each factor.

Because of the maturation of the SEO industry, which has arisen out of the tremendous diversification of the SERPs, a newer and better best practice has emerged: studying what the search engine is returning for your most important queries and then analyzing the top competitors for these terms.

Rather than looking for universal top-ranking factors, research the types of media Google, Bing, or other entities are returning for your top keyword phrases. Do you see strong organic competitors? Featured snippets? Image packs? Video results? Local packs? How big of an inroad is AI making in your corner of Search at this point, and how will your organization respond to it?

Learn to conduct a good organic competitor audit and a good local competitor audit and to track and understand the SERP features that Google is surfacing for your audience. Master the basics of on-page, off-page, and technical SEO, and then look for ways not just to compete with the top results but to differentiate your brand in the SERPs so that you stand out to real people as the best and most relevant resource for their queries.

Be wary of claims you may encounter of offers to make your company #1 in the organic SERPs or sources that empirically state that they know what search engines' top ranking factors are. Only the search engines have this information, and SEO is all about the ongoing study of this topic as search evolves. Your knowledge of SEO basics learned on sites like this and through SEO tools, paired with your experimentation in your particular market, will be your best teachers as to which factors and strategies are meeting your goals for SERP visibility and maximum conversions.

Google Search Console and Analytics

• Google Search Console: This free tool helps you monitor and maintain your website’s presence in Google search results. It provides insights into search traffic, impressions, clicks, and alerts for technical issues and security threats. Using Google Search Console, you can identify and fix issues affecting your website’s performance in search results.
• Google Analytics: Another free tool, Google Analytics, helps you track and analyze website traffic, behavior, and conversion rates. It provides insights into user demographics, behavior, conversion rates, and data on website performance and technical issues. With Google Analytics, you can better understand how users interact with your website and make data-driven decisions to improve your SEO strategy.

Moz free tools

Moz offers a suite of free tools that can improve your SEO strategy and efforts:

• Keyword Explorer: This tool helps you discover and prioritize the best keywords to target for your SEO campaigns. It provides insights into keyword search volume, difficulty, and organic CTR, enabling you to optimize your content for relevant search terms.
• Link Explorer: Use Link Explorer to analyze your backlink profile and gain insights into your domain authority. It helps you identify opportunities for high-quality backlinks and understand your site's link-building progress.
• Moz Bar: The Moz Bar is a free browser extension that provides instant SEO metrics for any web page. It allows you to analyze page SEO, domain authority, and link metrics, all while browsing the web.
• Competitive Research: Moz's competitive research tools allow you to analyze your competitors' SEO strategies, uncover their top-ranking keywords, and identify areas where you can gain a competitive edge.

These tools are essential for website owners and SEO practitioners aiming to improve their search engine rankings and drive more organic search traffic. By leveraging Moz's free tools, you can conduct effective keyword research, analyze backlinks, and gain insights into your competitors' strategies, all of which are crucial for a successful SEO strategy.

Moz offers the best resources on the web for learning SEO. If you're entirely new to search marketing, start at the very beginning and read the updated Beginner's Guide to SEO. If you need advice on a specific topic or want to explore more content for all levels of expertise, check out our learning options below.

SEO Learning Center

You are here! Explore free articles like this on a wide range of topics, from SEO basics to local search strategies for mobile and international sites. The Learning Center is organized by topic for easy navigation, and each article includes links to other content you may find helpful along the way.

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For those serious about investing in their SEO education, Moz Academy offers an extensive catalog of on-demand coursework led by expert instructors and designed with hands-on learning in mind. In addition to a variety of courses for all skill levels, we offer the opportunity to earn valuable industry credentials with our world-class certifications in SEO EssentialsTechnical SEO.

How-To Guides

Written and compiled by the industry's top experts, our SEO guides on everything from auditing your site for technical success to hiring the best SEO managers are organized by skill level and available for free.

The Moz Blog

Long regarded as one of the most valuable places for SEO information, the Moz Blog is easy to explore by category and includes contributions from experts across the industry. The blog houses our popular Whiteboard Friday series and valuable updates several times per week on all areas of SEO.

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Our webinar series includes talks on the latest innovations in search marketing hosted by Moz's team of subject matter experts. It's the marketing conference experience on demand.

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