I was wondering if one is better off to have relative URL's for internal links vs absolute URL's?<a href=aboutus.html>About us </a>vs<a href=http://www.example.com/aboutus.html>About us </a>Do search engines prefer any particular format?Also are relative URL's helpful to ensure the website is secure particularly if you have gone in for SSL certification for the website?
Internal links URL and SEO
seo;https;links
This is something we actually looked into recently. We have heard that absolute URLs have a number of benefits over relative such as preventing scrapers, preventing duplicate content issues and increasing Google's chances of crawling your entire site when it reaches it's crawl limit (see this Moz video for more depth). However, we use relative URLs as we have staging sites which contain our internal links, and we would have to change them all when we deployed updates to reflect the different domain names. Therefore, it depends on what works best for you.