The component of a computer that performs calculations and processing tasks is the central processing unit (CPU). The CPU interprets instructions from programs and executes them, making it essential for overall system performance. It determines the speed and efficiency of a computer by handling arithmetic, logic, control, and input/output operations. The CPU works in conjunction with memory and other hardware components to complete tasks and process data. Modern CPUs often consist of multiple cores, allowing for parallel processing to improve multitasking and computational power.