Vector Vs. Raster Graphic
Vector Artwork: In vector artwork, the graphics are based on mathematical relationships between points, which allows the image to be scaled to any size without any loss of quality. Vector artwork is typically created with an illustration program (such as Adobe Illustrator), and is the preferred format for logo creation because of its crisp lines and scalability.
Raster Artwork: Raster artwork is made up of tiny dots called pixels. Each dot can be a different color, allowing for rich, full-colour photographic images. Raster artwork files are typically created with photo-editing software (such as Photoshop). In general, raster artwork cannot be increased in size without losing quality.