Any picture you see on a Web page is a bitmap. Bitmaps come in many file formats, such as GIF, JPG, TIF, BMP, PCT, PCX, and DIB (Device Independent Bitmap). They can be read and edited by paint programs and image editors such as Photoshop or Paint Shop Pro. As its name suggests, a bitmap is a map of dots or pixels. If you zoom in or try to scale up a bitmap, it will look blocky.