What are relative and absolute positions?

Answer 1

Absolute links go to a specific location. They're usually very long and complicated, and if the item linked to is ever moved from that exact location, it won't be found.
Ex: C:\Users\guest\Desktop\WelcomePage.html

Relative links are like a shorthand. They start looking where the link is used, and all you write is where to go from there. This makes things easier to move around to other folders, devices, etc.
Ex: \Audio\demo.wav

Answer 2

It's sounds like you are mixing two differents context ^^

On one side, you have 'relative' and 'absolute' concepts for the css property 'position', and on the other, the 'relative' and 'absolute' concepts of Urls ( paths - in <a> link tags or others, attribut 'href', in <img> or others, 'src', in css embeded in 'url()'... ).

That's two things totally differents: about which one are you asking?