|One of the advantages of a more advanced video card is that it reduces the workload on the CPU. |
Take the example of drawing a line.
In very old video systems the CPU would have to calculate the position of each pixel and then put the necessary data in video memory. This was very time consuming.
In a more modern video system the CPU simply tells the video processor "draw a white line between points x and y", and then continue with other things. Modern video cards can do far more complex things than that, all with little intervention by the CPU.