Answer is:
CPU
Explanation:
The "brain" of a computer is often considered to be the Central Processing Unit (CPU). The CPU is the primary component responsible for executing instructions, performing calculations, and managing the flow of data within the computer system. It acts as the central processing and control unit, interpreting and executing instructions from computer programs. The CPU is a critical element in a computer, often referred to as the core processing unit or brain due to its central role in carrying out the computing tasks necessary for the operation of the system.
