Classes of Devices and Modules

The Linux way of looking at devices distinguishes between three fundamental device
types. Each module usually implements one of these types, and thus is classifiable as a
char module, a block module, or a network module. This division of modules into different
types, or classes, is not a rigid one; the programmer can choose to build huge
modules implementing different drivers in a single chunk of code. Good programmers,
nonetheless, usually create a different module for each new functionality they
implement, because decomposition is a key element of scalability and extendability.