A keyboard can be defined as a device that uses a number of keys for data entry. To enter the data through a keyboard, one needs to press the keys. Traditionally, keyboards have been divided into two broad categories--alphanumeric keyboards and musical keyboards.

The keys of an alphanumeric keyboard are usually marked with letters, numbers and some signs; for example, a computer keyboard or a typewriter. The musical keyboard has key for each note. Many musical instruments use these keyboards, most notably pianos and synthesizers.

A standard layout of numbers, letters and punctuation is known as the QWERTY keyboard. This is because the first six keys on the top row of letters spell QWERTY. It was designed in the 19th century for mechanical typewriters. Most of the keyboard users prefer the QWERTY layout, although an alternative layout called the Dvorak keyboard also exists.

The latter has also been in existence for the last seven decades, but it is still not very popular among users. It was designed by August Dvorak and William Dealey in the 1920s and 1930s. Some of the users of the Dvorak keyboard claim that it helps you to type much faster than a QWERTY keyboard.

Today, keyboards are available in wide variety of colors, sizes and shapes. For children there are specially designed baby keyboards readily available at affordable prices.

While purchasing a keyboard, one should ensure that it is compatible with the equipment it is going to be attached to. Keyboards can be attached to a wide variety of equipment. Some keyboards, which use wireless technology, are commonly known as cordless keyboards. The most frequent use of keyboards, nowadays, is to operate computers, musical instruments and some other handheld computing devices.