CPU is made up of several million tiny electronic switches called transistors. These operate at very high speeds, turning on and off to assemble patterns which users find meaningful. Remember Data vs. Information.
Information is the product of computers organizing data into meaningful patterns.
With computers, everything is represented by numbers. Bits aligned in specific patterns stand for characters. 7bit code which defines 127 characters. 65,536 different characters or symbols. The components of the system unit are usually contained in a metal or plastic case.