What is the difference between vector and pixel based graphics?

I'm not an expert on this, but I think that when you draw with vectors, you're drawing lines, which means that when you resize the quality won't be affected because the lines will have the same angles between them, but when you draw with pixels, you draw a limited number of pixels, and this causes what you draw to deform when resizing, the software you use will try to minimize the affect, but it can be obvious

Vectors can be stretched while pixel graphics are based on the pixels you see on screen and thus develop a jaggedness when stretched.

Vector- is a flat and sharp colors.
Pixel-is a base of two or more shades of 1 color.

vector graphics we use mathematics instruments such as pen , and pencil (lines) which is not effect on the quality / resolution while re-sizing or changing the file , raster is talking about how many color dots on our disign .(DPI - dots per inches) .