301 Redirects:

A 301 redirect is a method used to permanently redirect one URL to another. It's an HTTP status code that indicates that a webpage has been permanently moved to a new location. When a user or a search engine bot tries to access the original URL, they are automatically redirected to the new URL specified in the 301 redirect.
301 redirects are commonly used when a website undergoes a redesign, changes its domain name, or moves content to a new location. They help preserve SEO value by transferring the ranking signals from the old URL to the new one.
Backlinks:

Backlinks, also known as inbound links or incoming links, are hyperlinks on other websites that point back to your website. They are a crucial component of search engine optimization (SEO) and are considered a vote of confidence from one site to another.
Backlinks are valuable because search engines like Google use them as one of the factors to determine the authority, relevance, and credibility of a website. Websites with a higher number of quality backlinks tend to rank higher in search engine results pages (SERPs).
Backlinks can be obtained through various methods such as creating high-quality content, outreach campaigns, guest blogging, and participating in online communities.