A processor, often referred to as a central processing unit (CPU), is the primary component of a computer that performs calculations and executes instructions. It acts as the brain of the computer, processing data and managing tasks. Processors are measured in terms of speed, typically in gigahertz (GHz), which indicates how many cycles per second they can perform. Modern processors can have multiple cores, allowing them to handle several tasks simultaneously. This multi-core design improves performance for applications that require significant processing power, such as video editing or gaming. Popular processor manufacturers include companies like Intel and AMD.