Hello again....since i want to know what is bitcoin for you...and what you think about anothers cryptocurrencies like ethereum,litecoin,dogecoin,eth classic,zcash,dashcoin,monero,golem and others...
Let's put it this way: Bitcoin is the mother of all crypto currencies since it's the first digital currency that uses blockchain. Alternate coins on the other hand are another digital currencies which of course run on a blockchain too with different usage. Some alt coins were created from a hardfork of a certain coins or altcoins too.