Raster images consist of a grid, or raster, of small squares or pixels.
When working with these images, you edit groups of pixels rather than objects or shapes. Raster-based images are best for continuous tone images like photographs or images created in painting programs. Raster images are resolution- dependent and appear jagged, fuzzy and lose detail if they are scanned or created at a low resolution and are then printed at a high resolution. Vector images are made up of mathematically defined lines and curves called vectors. These resolution-independent images then have a specific location on a page making it easy to resize, move, or change color without losing detail.