keyboard is the primary input device of the PC. Each keyboard has keys of alphabets like a to z and numeric keys like 0 to 9. Using the combination of various alphabets and numeric keys user enters commands and text. The keyboards are similar to the type writers. However, the keyboard has many additional keys.
Computer keyboards have no significant changes since they were introduced. The only changes are the number of keys in the original keyboards. Present day keyboards have 101 or more keys. Each of these keys performs a different operation.

Identifying Different Types of Keyboards

To Identify the different types of keyboard we need to check the following things:
1.) Type and Number of Keys.
2.) Interface.

Types of Keyboards:

There are several types of keyboards that are in use today. All these keyboards differ slightly in the layout. Different types of keyboards available in the market are based on the number of keys they contain and are described below.

101- Key Enhanced Keyboards

IBM introduced the 101-key enhanced keyboard in 1986, as part of the IBM PC/AT Model 339. Enhanced keyboards with 101 keys are also used today. Present day fancy versions of a computer keyboards are based on this layout. The 101-key enhanced keyboard proved to be very popular amongst all users. However, it had one major drawback – a small Enter key.

101-Key Enhanced Keywords

102-Key Enhanced Keyboards

The 102-key enhanced keyboards were introduced to make the usage of keyboards easier for non-English users. There are several versions of this layout, all of which are almost identical to the 101-key enhanced keyboard. Some languages that use considerably more than 26 letters have 102 key keyboard layouts e.g. Spanish and Hungarian.

102-Key Enhanced Keywords

104-Key Windows Keyboard

Microsoft introduced the 104-key Windows keyboard as an improvement over the 101-key enhanced keyboard. These two keyboards are almost identical. The 104-key Windows keyboard only had an addition of three special keys that initiated Windows related functions.

These three keys included two identical keys to open the Start menu and one key to perform the right-click operation using the keyboard. The 104-key Windows keyboard offers additional features and ease of operation which were not provided by the 101-key enhanced keyboard. It has therefore replaced the 101-key enhanced keyboard on most personal computers.

104-Key Enhanced Keywords

Multimedia Keyboard

Multi-Media keyboards have additional buttons for launching the commonly used software. Some multimedia keyboards also have the functionality to open mail clients. multimedia player, Internet browser, and search programs. Some multimedia keyboards have the functionality to go back and forth in a Web browser, to raise or lower volume and jump from one file to another in a multimedia player.

Multimedia Keyboard

Wireless Interface

In case of wireless interface, keyboards are connected to the system using either infrared or Bluetooth technology.

Cordless/Wireless Keyboards
The Cordless keyboards are the latest addition to the family of keyboards. The usage of cordless keyboard has a lot of advantages. You can place the keyboard according to your convenience and comfort. It is based upon Infrared technology. Cordless keyboards run on batteries.

Cordless Keyboard

Bluetooth Keyboards

Bluetooth Keyboards uses the Bluetooth technology. Bluetooth is a short-range wireless technology. It eliminates the use of cables. The main advantage of Bluetooth keyboard over the wireless is that wireless keyboards ranges up to 6 feet, where as Bluetooth keyboards ranges up to 30 feet.

Bluetooth keyboards can connect directly to PCs that have built-in Bluetooth technology. For Computers without built-in Bluetooth technology, people need only plug in the micro-receiver to a USB port to connect the keyboard to the PC; the keyboard and receiver are pre-paired during manufacturing so that they automatically connect when plugged in.