1. Assigns a unique value to a input of a certain type.
2. It can be used to help the military,and to figure out peoples passwords.
3. You can also use it, so you can make a very hard to figure out password, that way hackers have more trouble. You can use this if you want to trick some of your friends. If you work in the military you could probably become some sort of spy. It is important also to use if you are some sort of computer coder to wright programs. Functions are also good to know when doing Algebra II.