Office Administrative Assistant Practice Exam 2025 – Complete Study Resource

The CPU, or Central Processing Unit, is often referred to as the "brains" of the computer because it is responsible for executing instructions and processing data. It performs the calculations and logical operations necessary for running programs and managing the computer's operations. This role of the CPU is central to the functioning of a computer system, as it interprets and executes the commands from the software.

In contrast, while the hard drive is used for data storage, RAM (Random Access Memory) temporarily holds data and program instructions that are actively in use, and the motherboard serves as the main circuit board that connects all components of the computer. Therefore, while all these parts are crucial for the overall operation of a computer, the CPU's primary function of processing and executing instructions uniquely qualifies it as the "brains" of the system.