A microprocessor is an integrated circuit on a tiny silicon chip that contains thousands or millions of tiny on/off switches, known as transistors. The transistors are laid out along microscopic lines made of superfine traces of aluminum that store or manipulate data. These circuits manipulate data in certain patterns, patterns that can be programmed by software to make machines do many useful tasks.
What do they do
One of the biggest tasks microprocessors perform is acting as the brains inside a personal computer. The microprocessor functions through two memories. The read only memory, or ROM, is a program with a fixed set of instructions and is programmed with a fixed set of bytes. The other memory is the RAM, or random access, memory. The number of bytes in this memory is variable and lasts for a short term. If power is switched off the RAM is wiped out. The ROM has a small program within it called the BIOS, or the basic input output system. The BIOS tests the hardware on the machine when it starts up. It then fetches another program in the ROM called the boot sector. This boot sector program executes a series of instructions that helps to utilize the computer effectively.