I heard the knowledge of bitcoin (btc)and ETH since 2016 and i want to know the difference between altcoin and BTC and ETH.

and how influential is altcoin because beginners that ask question is really or interested to know which I am willing to know.

I know some people will react to this topic violently and some will respond with manner,
I am here to know what i don't know because I believe that knowledge is power and also the beginning of success.