The CPU is measured by its clock speed in MHz. One megahertz is one million cycles per second. The first IBM PC CPU, the 8088, ran at 4.77 MHz, today's PCs can exceed 700 MHz. With the chip is a math coprocessor which handles floating point calculations, like algebra and statistics. A math coprocessor, also called an FPU, handles most of the numeric operations.
Most processors have an internal cache which stores frequently used data and instructions.
Cache is broken up into two classifications, L1 which is the internal cache and L2 which is the external cache. Each processor have buses that go along with them. The data bus is used to send and receive data. The address bus is used to describe memory address locations. Each CPU handles a different width of each of the different types of buses.