If you’re new to computers or if you just want a refresher, here’s a a basic description of the important parts inside a computer.
Chances are you know what a computer is but, for the record, at the end of the day it’s a counting machine. Modern day computers process information in the form of binary numbers. Binary is a counting system that uses only the numbers one or zero, not zero through nine. A computer is really a glorified calculator that can do millions of binary calculations every second. These calculations are the basis for computer programming and together they form commands, and these commands all grouped together tell the computer to do tasks. Programs can contain millions of commands that have the ability to take information from a computer user and do something with it to produce a useful result.
Types of Computers
While there are dozens of different types of computers, the ones I’ll focus on here are personal computers. There are typically two types. Those built buy Apple Computer, which are usually called Macs, and those referred to as PCs, short for “personal computers”. Technically, Macs are PCs too, but the term PC usually is used to mean non-Mac. The main difference between the two types of computers is the operating system, or the software that controls the computer. Most PCs run the Windows operating system; Macs run Mac OS X (Ten). There are other operating systems too. Programs that run on Windows don’t usually run on Mac OS X; programs that run on Mac OS X don’t usually run on Windows (there are some exceptions).
So what is a computer made up of? Well, here’s a break down of the most important parts inside a computer.
A Central Processing Unit (CPU)or just processor, is the brain of a computer. This is does all the binary calculations to make programs run. You’ll here people talk about a “Pentium” or “Athlon” or “PowerPC” (in the Mac world). They are referring to the type of processor in the computer.
A hard drive is the storage device on a computer that holds all the information needed to operate a computer, including programs, the operating system, and data created by a computer user. A hard drive is sometimes referred to as a “hard disk”. For the record a hard drive is not the beige (or taupe or black) plastic box that all the computer components are in. A hard drive is actually a bunch of disks inside a metal case inside that plastic box that spin very quickly. There are special heads that read and write information onto the disks. The heads are similar in concept to the arm on a record player. They move back and forth over the surface of the disks as they spin. They use magnetism to read and write binary information (ones and zeros, remember?).
RAM is short for Random Access Memory. This is also referred to as simply “computer memory”. This is where the computer does short term tasks. When a program runs, a copy of it moves off the hard drive and into the processor. Then when the processor wants to accomplish special calculations or do specific tasks, it sends the task to the memory where calculations are made. When that’s done the task is wiped out of RAM. If you “run out of memory”, it means that there are too many tasks in RAM to fit any more. Sometimes these tasks use the same part of the memory and this causes a computer crash. A crash means the computer stops working. When you switch off the computer and restart it, the RAM is wiped clean and the computer should operate normally again. A hard drive is not wiped clean during a restart. It retains all information even when the computer is switched off.
It helps to think of a computer as a workshop. The carpenter in the workshop would be the processor. The workbench would the RAM where specific tasks are done. The shelves where all the tools and materials are kept make up the hard drive. The one who makes things happen in the workshop is you!