< a href=”http://mywebsite.com/mypage.html”>
A RELATIVE LINK: is like this
< a href=”/mypage.html”>
The relative style link will make the page load alittle faster as it is not going outside the /public_html/
The absolute link takes that request outside of, as it is a new link that must hit apache first.
Will it make a big difference? No unless your site is getting mega requests/hits you most likely will never notice. exception is a very s l o w server in which case you should move to a better host any way.
If you site is scraped by scrapers, rss feeds,ect then by all means use the absolute.
SEO Value? none