Google Webmaster Tools used to identify the links in two categories:
- Links from within your site (Internal Links), i.e., only those links that started with your site's exact URL &
- Links coming from other sites (External Links)
For the site, www.example.com/users/catlover/, links from www.example.com/users/catlover/profile.html would be categorized as internal, but links from www.example.com/users/ or www.example.com would be categorized as external links.
In the recent update, if you add either example.com or www.example.com as a site, links from both the www and non-www versions of the domain will be categorized as internal links. This also implies to include other subdomains, since many people who own a domain also own its subdomains—so links from cats.example.com or pets.example.com will also be categorized as internal links for www.example.com.
If you own a site that’s on a subdomain (such as googlewebmastercentral.blogspot.com) or in a subfolder (www.google.com/support/webmasters/) and don’t own the root domain, you’ll still only see links from URLs starting with that subdomain or subfolder in your internal links, and all others will be categorized as external links. We’ve made a few backend changes so that these numbers should be even more accurate for you.
Note that, if you own a root domain like example.com or www.example.com, your number of external links may appear to go down with this change; this is because, as described above, some of the URLs we were previously classifying as external links will have moved into the internal links report. Your total number of links (internal + external) should not be affected by this change.