New to diesels somewhat as far as this efi live goes I'm interested in it I just don't understand it I guess. Any help?

 

well, its basically the tool to make the ecm do as you wish.
kinda of like what a code writer does for a computer.
you have to know what you are doing, for the maximum potential in MPG and horsepower you have to be a little computer literate. basically you just have to be able to email, download files, run the program and connect to the trucks ecm and download the information using your computer.
people can tune the vehicles for you so it takes the hard part of it out for you.