A coprocessor is an auxiliary microprocessor designed to supplement the functionality of its host processor typically with a more specialized set of operations such as floating point arithmetic, string processing, and encryption. Generally, a distinction is made between a coprocessor and a generic accelerator in how the interaction between the host processor and the coprocessor is done. Whereas a coprocessor is architectural and is typically connected to the internals of the host processor which then passes it instructions to execute, an accelerator is typically viewed as an independent I/O device which is programmed though an interface.