An input method is a tool in either an operating system or a software program that enables the user of a computing device to use the keyboard to type characters that are not represented on the keypad of that particular device. This method is frequently used for inputting characters from a language with a different alphabet and for enabling letters to be typed with a numerical keyboard. It was originally created to accommodate a group of Asian languages on keyboards with the Latin alphabet, though it has now spread to several other languages and alphabets.
The first input method was created to manage the internationalization of CJK computing, a term that stands for the Chinese, Japanese, and Korean languages. Since then the term CJKV, which includes Vietnamese, has been coined to cover all of the East Asian languages upon which input method is most frequently used. Input method can be implemented via a specially-programmed editor or with several other methods including the use of dead keys, the pinyin method or the Cangjie method.
Many systems use an input method editor (IME) to translate one alphabet to another or to a series of characters. The IME was created by Microsoft and has now come to be adopted by most major operating systems and technical companies involved in internationalization. Primarily due to the memory it requires, most systems will not come with an IME installed. For the same reason, most input method editors will allow a user to pick which languages to install and even make selections within a language. For example, a user can choose between traditional and simple Chinese.
The Cangjie method was created in 1976 to enable the input of Chinese characters. It was originally used for traditional, but now also manages simple, Chinese. In this system, each key is assigned a particular graphic, such as a cross or a certain kind of slash. Multiple keystrokes are then combined to make each character.
Another method used for Chinese is the pinyin method. A pinyin is a system by which Chinese characters are translated into words spelled with the Roman alphabet. When using this method, pinyin words that are typed on a keyboard are translated into Chinese characters on the screen.
Dead keys can also be used as an input method. These are keys that do not input anything when pressed alone, but when used before a letter will add a mark to that character. For example, an accent mark may not appear when the key is pushed, but if the letter "a" is selected afterwards, an accent will appear over that letter.