You should know that every cryptocurrency that isn’t Bitcoin is referred to as an “altcoin”. Some altcoins have been around for years and control a sizable amount of the crypto market. The two major altcoins are:
1 - Litecoin. This currency was designed by a former Google engineer with the explicit goal of being “the silver to Bitcoin’s gold”. Transactions with Litecoin are faster and new coins are easier to mine.
2 - Ethereum. Launched in 2015, this altcoin was launched as part of a decentralized software platform to facilitate web development and crypto transactions. Today it’s one of the major players in this market.
You can learn more about all this over at VanillaCrypto.