Basically, the computer part of your computer. Sometimes means just the processor, sometimes refers the the entire box.
The CPU contains the chip or main processor of a personal or desktop computer. It performs the basic tasks and functions of the computer, and is often called the "brains" of the computer. The CPU may also refer to the housing or motherboard that contains the chip.
The brains of your computer. In fact, the main silicon chip that runs the operating system and programs, and controls essential operations.
The CPU is the core of the computer. It's one of the smaller pieces, consisting of a flat square of silicon, but it contains most of the computer's complexity, in the form of millions of transistors. When the computer is executing programs, all of the instructions as well as the data are fetched from RAM and processed by the CPU.
The portion of a computer that executes programmed instructions, performs arithmetic and logical operations on data, and controls input/output functions.
The part within the computer that interprets and executes the instructions the user gives the system. It is composed of an arithmetic logic unit, a control unit, and some memory. In a personal computer, it is a single chip.