Ever wonder what’s inside a computer? We can break it down into three easy descriptions:
CPU (Central Processing Unit) The ‘brain’ of the computer. It processes the instructions (see article Bits and Bytes) at an amazing rate. The faster it can process an instruction, the faster the computer will respond. For example, in our previous article, we used the command (instruction) PRINT. In a computer that has a CPU that can read 1,000,000 instructions per second will respond in about 1-2 seconds to print your document. A CPU that can read 2,000,000 instructions per second will respond twice as fast and so on. The speed (instructions per second) is calculated in units of Gigahertz (GHz – Billions of cycles (instructions) per second), so when you are shopping for a PC or laptop, take a look at the speed of the CPU and decide which one you would want to use, but let’s read about memory also, as these two items go hand in hand.
Memory (Random Access Memory – RAM) This is the area where programs (apps) that you are currently working on stores lives. For example, when you call up Microsoft Word, the instructions that comprise the program so that it will work will be stored in memory. In addition, the work that your are doing (e.g. typing a document, inserting a picture, using spell check or even changing a character to bold) all are read from the instructions that were loaded into the memory).
Memory is volatile; that is, the information stored there is not stored there permanently. Rather it is lost as soon as you power off the computer. This is why it is wise to frequently ‘Save’ you work as you proceed, since if the computer unintentionally shuts down (e.g. an electrical power hit), all work that you did not save yet will be lost.
Memory is referenced by units of Metabytes (millions of bytes). A typical PC has four – eight MBs. Some of the more expensive computers have up to 32MBs. Why is this important? Because the more RAM you have, the faster, yes the faster the computer will run. This is because it can store more instructions at one time which then can be read by the CPU faster; therefore, besides looking at what the CPU speed is on a PC or laptop, look and see how much memory it has.
TIP: Memory is the most important component in a computer, so if you see a computer that has a CPU of 1.6 GHz and memory of eight MBs and then you find another PC that has a CPU speed of 3Gz but only four MB of RAM, select the fist, as more memory in a machine will override CPU speed.
Hard Drive (HD) When it comes to storing data, the hard drive is the opposite of memory. Whatever is stored on the HD remains there until you delete, so when you ‘Save’ your work, you are actually moving it from temporary memory onto the permanent storage area of the hard drive.
Hard drives come in many sizes. Typically, the more HD space offered on a computer, the more expensive it will be. Standard HD sizes run fro, 500 Gigabytes (500 billion bytes) to 5 Terabytes (5 trillion bytes). How do you decide? If you only use your computer for the Internet, email and occasionally use Microsoft Office, you would most likely not need a hard drive larger then 500 MB, but if you take a lot of pictures or videos and then want to store them onto you computer, you should have a disk drive of at least 1 Terabyte.