What are altcoins?

The word “altcoin” is an abbreviation of “Bitcoin alternative,” and thus describes every single cryptocurrency except for Bitcoin. Altcoins are referred to as Bitcoin alternatives because, at least to some extent, most altcoins hope to either replace or improve upon at least one Bitcoin component. Some altcoins examples are etherium, monero, pesobit, time etc..For more info about altcoins you can go here https://en.bitcoin.it/wiki/Altcoin