LOGO FILE TYPES 101
There are two different types of files when it comes to graphic design. One is called a bitmap (also known as a “raster” image). The other is called a vector file. Each has its own place in graphic design, depending on the work being done.
Bitmap graphics are the most common graphic format for the web and home/office computers. Bitmap formats often end in .tif, .jpg, .gif, .png, .bmp, .psd, and sometimes, .pdf, among others. Digital photographs and files created using scanners are bitmap images.
Bitmap images are composed of pixels which are tiny squares, each containing specific color information. Pixels are not discernible to the naked eye. Images can contain thousands of pixels, making bitmaps ideal for complex coloring or extreme detail.
Because bitmaps are made up of pixels, they are resolution-dependant. (Resolution refers to how many pixels are in the image.) Enlarging a bitmap makes the individual pixels more visible, sacrificing the quality of the image by making it appear blurry.
Bitmaps cannot be converted into vectors without being redrawn by a professional.
Vector graphics are mathematical creations consisting of points, lines, and curves which combine to form complex shapes. These shapes can be filled with solid colors, gradients, and even patterns. They are created using specialized design software. Vector format file extensions often end in .ai, .eps, .cdr, .fla/.swf, and sometimes .pdf, among others.
Because vector images are not made up of pixels, they are more simplistic in nature, unable to produce the same realistic detail as a bitmap.
Vector graphics are ideal for producing artwork which frequently needs to be presented in different sizes or colors. Logos especially fall into this category. A logo produced with a vector application can be scaled down to adorn a piece of letterhead or blown up to fit on a billboard with no difference in quality.
Vector files can easily be converted into bitmaps, but the original vector file should always be kept and maintained, as it will often be required any time it needs to be reproduced professionally.