what is a midi exactly

I have just acquired a new amp and keyboards, to go with my guitar and boss processor,and boss br684 mini studio. Now i have to learn how to innovate the the web, to post recordings, question: What does a midi exactly do. would it be helpful to me?

Although I hesitate to give Wikpaedia as a source it's a start.

http://en.wikipedia.org/wiki/Musical_Instrument_Digital_Interface

I don't get what you're trying to do. Are you wondering how to put recordings on the internet?