Bitmap Types

There are two types of bitmaps: device-dependent (DDBs) and device-independent (DIBs). DDBs were common in early (pre-3.0) versions of Windows. In fact, they were the only bitmaps available to developers. However, as display technology improved and as the variety of display devices increased among Windows users, certain inherent problems surfaced. For example, there was no method of storing (or retrieving) the resolution of the display type on which a bitmap was created, so a drawing application could not quickly determine whether a bitmap was suitable for the type of video display device on which the application was running. To solve this problem, Microsoft created DIBs.