Lambda

So can anybody tell me in a way one can understand it what the fucking lambda calculus does?

I'm the Lambda!!!!!!!!

Ski bi di bi di do bap do bap
Do bap do bap
Ski bi di bi di do bap do bap
Do bap do bap

I'm the Lambda!!!!!!!!

Ski bi di bi di do bap do bap
Do bap do bap
Ski bi di bi di do bap do bap
Do bap do bap

Everybody lisps one day or the other
So check out my message to you
As a matter of fact
Don't let nothing hold you back
If the lambda can do it
So can you