Raster Graphics & Vector Graphics

All digital graphic images can be divided into one of two fundamental types:
Vector Graphics and Raster Graphics (bitmap, pixel).

Raster Graphics (commonly called bitmap images) are made of pixels. Photographs are an example of a bitmap image. They have a fixed resolution and cannot be resized larger without losing quality.
Common bitmap file formats end in:  .gif   .jpg  .png  .tiff  & .bmp

Bitmap images typically have much larger file sizes than the same image as a vector graphic so they are often compressed to reduce their size. Bitmap images can be converted from one format to another with programs such as Photoshop.

Vector Graphics are images that have been created in a drawing program such as Adobe Illustrator. They use paths to create lines and curves at connecting points called "nodes" to store the graphic's information mathematically. Vector art is resolution independent; whether you enlarge or shrink the image, the output quality is never compromised. This is why logos should always be created in vector art format. Common file formats for vector art used in the commercial printing industry include: .ai  .eps  &  .pdf 

A common public misconception is that using “ > SAVE AS” and saving to another file format will somehow fix the problem. Pixel-based raster art will always be made out of pixels regardless of what file format one save the image as. It is possible to convert raster art into vector with methods such as “LIVE TRACE” in Adobe Illustrator, but the results are usually less than satisfcactory when used on a corporate logo. The only alternative to obtain a professional vector file of a reaster logo is tohave a professional graphic artist recreate the logo from scratch in the proper software.

Vector graphics formats are complementary to raster graphics. There are some instances when working with vector graphics is best, and other instances when working with a raster image is better.

Most marketing materials actually contain a combination of both raster and vector art formats. An understanding of the advantages & limitations of each format and the relationship between them is most likely to result in efficient and effective use of tools.

Understanding raster graphics v.s. vector graphics is important in choosing which design program to use for a particular project. Logos should always be created in vector art format because you want your corporate logo to be scalable — able to be enlarged without any loss of quality.