3.the contains the computer's "brain," the central processing unit (cpu).

The computer brain is a microprocessor called the central processing unit (CPU). The CPU is a chip containing millions of tiny transistors. It's the CPU's job to perform the calculations necessary to make the computer work -- the transistors in the CPU manipulate the data. You can think of a CPU as the decision maker.

The computer brain is a microprocessor called the central processing unit (CPU). The CPU is a chip containing millions of tiny transistors. It's the CPU's job to perform the calculations necessary to make the computer work -- the transistors in the CPU manipulate the data. You can think of a CPU as the decision maker.

Credits too google!