Processor (computing)

In computing and computer science, a processor or processing unit is an electrical component (digital circuit) that performs operations on an external data source, usually memory or some other data stream.^[1] It typically takes the form of a microprocessor, which can be implemented on a single or a few tightly integrated metal–oxide–semiconductor integrated circuit chips.^[2][3] In the past, processors were constructed using multiple individual vacuum tubes,^[4][5] multiple individual transistors,^[6] or multiple integrated circuits.

The term is frequently used to refer to the central processing unit (CPU), the main processor in a system.^[7] However, it can also refer to other coprocessors, such as a graphics processing unit (GPU).^[8]

Traditional processors are typically based on silicon; however, researchers have developed experimental processors based on alternative materials such as carbon nanotubes,^[9] graphene,^[10] diamond,^[11] and alloys made of elements from groups three and five of the periodic table.^[12] Transistors made of a single sheet of silicon atoms one atom tall and other 2D materials have been researched for use in processors.^[13] Quantum processors have been created; they use quantum superposition to represent bits (called qubits) instead of only an on or off state.^[14][15]