Computers store information by using switches (on-off switches, like the ones used for turning on/off lights, except a lot smaller, and implemented with electronics - i.e. no moving parts).It works like this. Suppose you want to store some information. You go down to the hardware store and buy a switch. OK, now you have a binary digital storage device. "Digital" means basically that it only can have one of a set number of possible states, and "binary" means that it can only have two such possible states. That is, it can be either on or off. An example of a device that is neither binary nor digital would be a slide rule. Slide rules have an infinite number of possible states, and such devices are called "analog" as opposed to "digital".So far so good. You have a binary digital storage device. Now you just have to decide how to represent information on it. You have two possible states you can use, which means you can "store" two pieces of information by specifying a "code".Let's use numbers to represent the possible states of the switch. "0" means the switch is off (up) and "1" means it is down. So let's make a weather code.0 = it's raining1 = it's notSo now you have a personal digital assistant which stores the day's weather report. So that's pretty cool, and you go out to show it to your friend. You meet your friend, and pull out your switch and look at it (information retrieval), remember the code (information processing) and say, "look, according to my PDA, it is raining".Your friend says, "that's nice...but as a matter of fact it stopped raining an hour ago". And then she pulls out her PDA and shows you how she has the very same info, plus a copy of War and Peace, stock market quotes, and a complete mirror of "alt.liberal.arts.disgruntled". That's because your friend's PDA has about 100 million more switches than yours.So you are pretty crestfallen, and go back to the hardware store and ask if they have 100 million switches in stock. They don't, they only have 23. But that's a start, so you buy them and go back to your living room, where you try to assemble them into a more powerful PDA.Now you have 23 switches. How can you store more information? Well, since you have more switches, your PDA can have more possible states. For example, suppose you take two switches and put them side by side. Now, instead of two possible states, you have four:00011011This is looking promising, so you put another switch alongside the other two:000001010011100101110111