Processor

A processor, also called a central processing unit (CPU), is the primary computing element that executes program instructions. It performs basic arithmetic, logic operations, data movement, and control flow, coordinating the activity of other components.

Modern processors are built around cores that execute instructions following a defined instruction set architecture (ISA) such as x86-64, ARM, or RISC-V. They use pipelines, caches, and sometimes out-of-order execution to improve throughput; many chips include SIMD or vector units for parallel data processing.

On-chip caches (L1, L2, L3) reduce latency by storing frequently used data. The performance depends on clock speed, IPC, cache size, and memory subsystem.

Processors are manufactured as integrated circuits, fabricated with lithography processes measured in nanometers. Modern CPUs may have multiple cores and support simultaneous multithreading.

They are used in personal computers, servers, mobile devices, embedded systems, and specialized devices. Some designs are integrated into system-on-a-chip (SoC) configurations that include memory, graphics, and I/O controllers.

Power consumption and cooling requirements affect performance and design trade-offs. Thermal design power (TDP) is a common metric.

Early processors were discrete transistors; the first microprocessors emerged in the 1970s. Since then, processors have grown in core count and features while shrinking process nodes.

Industry trends include heterogeneous architectures combining CPU cores with GPUs or dedicated AI accelerators, and expanding use in edge and mobile computing.