What's altcoin, litcoin and dogecoin got to do?
This is a good question indeed.
What have litecoin brought us? It was created for GPU-resistent and now we have scrypt ASIC already.
What have dogecoin brought us? It just tells us how important the coin community is towards the coin popularity.
What about the other hundreds of altcoin?
How long are you studying this things? How long am I going to need to understand all this?