Broadly speaking, there are two types of image file: vector images and bitmap images. Bitmap images consist of grids colored pixel by pixel. Vector images are designed using mathematical equations and geometrical primitives (points, lines and shapes) in programs such as Adobe Illustrator, Freehand, Corel Draw, Quark and a few others.
Bitmap art is identified with files ending in .gif, .bmp, .jpg., .png and .ncx. Vector files are typically saved as .eps, .ai or .cdr files.
There are several advantages to vector images. If you try to enlarge a bitmap image, your computer can only enlarge the size of the squares making up the image area. You still have squares; that is why bitmap images become jagged or ‘pixelated’ as you enlarge them. Vector images remain smooth because your computer merely re-computes the coordinates of the points and adjusts the vector equation constants, never sacrificing quality. The same art could be used for a business card or a billboard.
This is especially important if you need to print your images. While bitmap images may be suitable for some printing jobs, in most cases, especially with logo designs that incorporate numerous colors, a vector image is needed to achieve the quality of printing you expect.
Another advantage of vector images is that each set of lines in a vector image represents separate and distinct objects. Every object can be edited at any time. For example, let’s say you created a vector logo file with a rectangle in the background. You could open the vector at any time and change it an oval, square, or other shape.
If a professional graphic designer created your art or logo for you, they should have saved your artwork as a vector art file, even if they did not send that file to you. Some designers do not provide their clients with vector art because only clients with specialized software will be able to open the images.
In recent years, some logo designers have begun creating logos in Photoshop. This is a bad idea because the resulting image will be a bitmap file, and you will not be able to scale it infinitely. Make sure you know if you are getting a vector file or bitmap file before paying a graphic designer to create your logo.