The most obvious difference between a wireless keyboard and a normal one is that the former uses infrared beams to transfer data to the computer as opposed to the latter, which uses a wire. As you type, a beam of data is sent from your keyboard to a receiver on the computer. The major advantage of this is that eliminates one wire from the entangled web of wires from behind your desk. Many people also prefer to have a wireless mouse along with a wireless keyboard.
It may not be possible for a corded keyboard to be kept in a particular place that is most comfortable to you. This is possible with a cordless keyboard, provided that it is placed in a position where the infrared beam is easily reachable by the computer. This distance can be different for different computers, so it makes sense to check the specifications before buying a wireless keyboard. This feature can be a problem for the user if an object or person happens to block the path of the infrared beam or the angle of the keyboard is not right.
A wireless keyboard can be a valuable component is you are certain that the space between your keyboard and computer will remain free of physical obstructions. It will provide freedom and flexibility.
The ergonomic keyboard has been designed to relieve some of the stress caused by repetitive typing and make for more comfortable typing. Prolonged usage of the keyboard can cause carpal tunnel syndrome or repetitive stress injury, which can be very painful. The specially designed, contoured ergonomic keyboards are helpful in such cases and even recommended by doctors.
There is also a view that the traditional QWERTY layout is more stressful on the fingers and arms. Here, the unconventional Dvorak keyboard layout has been designed for those who subscribe to this theory.
While there are no design specifications for ergonomic keyboards, they generally have a contoured design for greater typing comfort, as opposed to the standard flat keyboard.
Much like mobile phone keyboards, these keyboards are backlit so that the keys are more visible even in poor lit conditions.
Often, when working at night, you may like to work only with the light of the monitor to prevent the glare of another light. An illuminated keyboard would be just the thing for you in such a situation. It is also great for multimedia presentations in boardrooms with dim lighting.
When buying an illuminated keyboard, look out for the options of being able to turn off the illumination when not required and to adjust the level of brightness.