What does this error mean when starting a new campaign

[ClaireH-184886]

hi just about to start a new campaign to i can monitor my website and i get this message up but not sure what this means.

Roger has detected a problem:

We have detected that the domain www.headlineplus.com and the domain headlineplus.com both respond to web requests and do not redirect. Having two "twin" domains that both resolve forces them to battle for SERP positions, making your SEO efforts less effective. We suggest redirecting one, then entering the other here.

can anyone please let me know why this message comes up please

[ClaireH-184886]

tried the redirect but did not like it and it looks like my hosting company have put the main domain without the www. so will read how to sort this out

[KeriMorgret]

It really depends on what your hosting company has done. Basically, you need to choose if you want a www in front of your URL or not, then make sure you set up your redirects properly. Your hosting company can help with this, or you can search for information on how to do this on apache, or there may be a Joomla plugin to help too.

[ClaireH-184886]

my hosting company done something the other day do you think this is what the problem is

[Lantec]

(http://)headlineplus.com and ww.headlineplus.com can be seen as seperate websites, you need to make sure that they are both (in your domain configuration) are pointing to the same place and maybe set-up a 301 redirect for http://headlineplus.com to www.headlineplus.com