The term ALT can refer to several different things. The three letter solution KEY is an abbreviation for the word 'KEYBOARD, ' which is a device used to input data into a computer. The four letter solution ELEV stands for 'ELEVATOR, ' which is a type of lift used to move people and goods between floors in a building. The three letter solution VAR is an abbreviation for the word 'VARIABLE, ' which is a value that can change in a program or equation. Finally, the four letter solution KEYS is an abbreviation for the word 'keys, ' which are small objects used to unlock doors or other items.