Raster vs. Vector

Raster Files:

Raster files are images made up of tiny squares, known as pixels. Typically the squares are so small that the image looks crisp and they are not detectable. However, when a raster image is enlarged, as often happens when blown up for a large sign or banner, the pixels become very obvious and the image quality does not look good. The quality of a raster file is measured in dots per inch, or DPI. For a printed image to appear crisp, it must be at least 300 DPI at the size it is to be printed at. A file pulled from a website is typically only 72 DPI. Common raster file formats are.JPEG, .TIFF, .PNG, .BMP, and .GIF.

Vector Files:

On the other hand, a vector file is a file made up of lines and arcs stored as coordinates. This means that vector files are made up of precisely defined entities, each with its own beginning and end, rather than lumpy groups of pixels as found inraster files. Vector files can be enlarged to any size without loosing any quality. Common vector file formats are .EPS, .AI, .SVG