What is a CPU and why is it called the brain of the computer?

Question

Whenever you buy a smartphone or a laptop, one of the first specifications you check is the processor or CPU. But what exactly does a processor do, and why is it so important?

Answer 1

The CPU (Central Processing Unit) is the main chip inside a computer that performs calculations and processes instructions. It is often called the “brain” of the computer because every task—whether opening an app, typing a document, or playing a video—requires CPU processing. The CPU performs millions of operations per second using its internal components like the arithmetic logic unit (ALU) and control unit.

Faster CPUs allow computers and phones to run smoothly even with heavy applications. The clock speed, measured in GHz, and the number of cores determine how powerful the CPU is.

Answer 2

Modern processors like Intel, AMD and ARM-based chips use multiple cores so the CPU can handle many tasks simultaneously. For example, a quad-core CPU can execute four instructions at the same time. This improves multitasking, gaming performance and overall speed. For basic computer knowledge exams, remember: CPU = main processor + executes instructions + measured in GHz + multi-core improves performance.