Any coin that is not bitcoin is an alt coin, and this includes tokens on the Ethereum network. There is some debate about what you become after you fork out from the original, so we have some clones like ETH and ETC, BTC and BCH which were made out of the same blockchain. These are called contientous forks.
Basically, in those cases, the development of the forked coin continues in its own direction. Imagine the trunk of a tree. It is one unit towards one point until it branches out and the branches each grow in its own direction. Some branches become part of the treetop, some wither and die.