Positioning trouble

[Nabil ab]

hi everyone, I just want to ask the professionals use is very simple question about CSS positioning step ahead of myself I started learning css a few months ago it was very very easy to me there was nothing complex about it at all. well not until I reach the positioning in CSS they will like a living ###### to me well of course I could understand that simple values which are fixed relative, absolute, and static and how the work and the relation between the relative and the absolute values. but one thing that I died understand in positioning is that when you position an element in html you need to position it according to let's say the full screen mood that's mean when you want to make the browser tab is in the full screen of your computer screen, but if you played with tab of the browser like you want to decrease or increase the size of tab the position will change now. so how does these positions work I don't know how they work when we can implement them in any HTML page. and also one more simple question is that if I want to center an elements like a box in the center of the HTML page but when I play with the tab at the dimensions it don't change from its position it stay and remains in the center of the HTML page not caring about the decreasing or the increasing of that tap dimensions.

[niche]

Use float instead. http://www.w3schools.com/cssref/pr_class_float.asp