A Raster file is a scanned document like a photo; once it is enlarged the quality of the image greatly drops. A Vector file is a file in which the quality of the image does not drop when enlarged. Vector files are made up of a series of lines, curves and shapes that can be edited without data loss. If you wish to enlarge your document or image, then Vector files would better suit your needs. On the other hand, if you wish to print your file at the same size or smaller, then Raster will do the job.