Vector Image:
Unlike JPGs and GIFs etc. vector graphics are not made up of a grid of pixels.Vector Graphics are made up of vectors which lead through locations called control points. Vector graphics use lines, shapes, curves etc which are based upon a mathematical expression to represent images. The other way for representing graphic images is through bit maps, in which the image is composed of a pattern of dots. Vector-oriented images are a bit more flexible than bit maps because they can be re sized and/or stretched. Because vector images are not made up of a specific number of dots, they can be scaled to a larger size and also not loose any image quality. You can usually identify a vector image by looking around the edge of the image, the image around the edge will always appear much more smoother whether you have zoomed in large or small, it will stay the same. Text is also one of the most common types of vector image. No matter how much you increase a font’s size, its look never changes.

Because vector images are recognized in a mathematical sense, the image size becomes much smaller and doesn't have a lot to take on when it comes to saving, so leaves you a lot more memory and space than a raster, therefore it is much easier to transfer from one computer to the next.