There are a whole load of computer hardware peripherals out there, so much and to such an extent that you may even shirk going to a computer shack in fear that you may go crazy looking at all the different types of peripherals out there.
However, this article will simplify things for you. These are the basic peripherals for computers:
The keyboard is a device which is used to input text into the computer. It is the most popular computer peripheral, and there are a couple of variants to the basic keyboard (different styles). For e.g., there are the extremely basic keyboards, which have the letters, numbers, keypad and function keys. Then there are some which have dedicated music keys (play, pause, next track, previous track, and volume control buttons) and internet keys (previous page, next page, e-mail, home page buttons) and some which are designed for good ergonomics. Some computers are starting to feature a virtual keyboard, which basically means that the keyboard is on the screen, and you input text by clicking on the buttons on the screen.
Ah, the mouse! What could we possibly do without it! Basically, the mouse is used as a means of inputting commands to the computer by controlling the cursor on the screen. The basic mouse had 3 buttons. Now, we have the normal 2 buttons, along with a scroll button. Some mice have a fourth button (quite small), which basically serves as a double click, which means wherever you have to click twice to activate a function, you just have to click this button once. Optical mice are a real blessing, as you don't have to go through the pain of cleaning the mouse ball every time it gets dusty.
Monitors are typically used to give you visual output. It is through the monitor that you can see what you're doing on the computer, and which enables you to control your functions.
Speakers are the devices that give you audio output. Nowadays, however, speakers do more than just audio output. They are used to give you the special effects when playing games, or when you're watching movies. Now, there are 5.1 (5 small speakers, and a single woofer) and 7.1 speakers (7 small ones and a woofer) which really enhance your computer experience.
Webcams are similar to video cameras in that they're used to transmit live visual data between computers through the internet. The advent of webcams have undoubtedly made the world a smaller place as you don't have to take a flight to visit a relative, rather you can visit him / her virtually at the comfort of your home.
These are the same as those you use in your iPods or mobile phone. Nowadays, headphones come with a mike, which enables you to talk with other people through the internet.
Summery: This article describes various hardware peripherals, the basic components that are used in day to day life, while also describing their functions and advancements.