re: #1 Bobibutu
It has a huge range of applications. Doing it in reverse is possible also, purposely changing a signal from its original form. That is convolution. For example if you wanted to add noise to a signal that cancels known noise in a particular transmission channel.

re: #2 Bobibutu
LOL.

What’s the matter Transfromnation? Don’t think computers doing math can “transform our nation”? Think I’m too haughty? Don’t like lots of words? Let us know! ;)