Dealing with graphics takes a lot of work. Modern computers usually have a separate computer built in just to help with controlling the monitor. This little computer has its own cpu and memory! The power and speed of this little computer, as well as its memory capacity, have a huge effect on how graphics are drawn to your screen. This little computer is referred to as a graphics controller card. The most common cards now are called SVGA. (You really don't need to know what it stands for but here goes: Super Video Graphics Array). Of course it gets way more complicated than this, but all you have to know is that there are fancier cards that do more and cost more, but you may not need the fanciest one out there for your first computer.