Vector computer artwork is composed of lines, curves and other elements that create an image. This is in contrast to raster artwork, which is composed of pixels that form the image.
Raster images, which are those stored in JPG, PNG and other common file extensions, contain a collection of pixels that make up an image. These files have a defined number of pixels. Vector images, in contrast, don't contain individual pixels but instructions for drawing an image using different shapes and directions.
One of the primary advantages of vector art is that the computer can draw the image file at any size and at any resolution without losing quality. Programs can resize raster images, but doing so generally incurs a loss of quality, especially when the programs expands the image to a higher resolution.
Typical computer monitors rely on pixels to create an image, so vector images have to be converted into raster format before the monitor can show them. However, some computer systems use vector monitors that draw lines on the screen instead of pixels. The Vectrex game console is one of the most famous examples of these types of monitors, and the home console followed a number of popular arcade games that used vector-drawing monitors to create the game's art.