The definition of an alternative coin, or altcoin, is any cryptocurrency that is not Bitcoin. This includes coins or tokens such as Ethereum, Cardano and Solana. As Bitcoin is considered to be the most prolific and established cryptocurrency around the world, it is considered to be the primary cryptocurrency. It has the largest market capitalization as compared to the other coins. There are a myriad of different, unique cryptocurrencies each with differing monetary values and utilities. All of which are considered to be altcoins. 

In order to differentiate themselves from other altcoins, many of these tokens and coins aim to have different utilities in order to compete with other cryptocurrencies and blockchains that they are competing against. This can also include providing better alternatives to big players like Bitcoin. For example, Litecoin used a different proof-of-work (PoW) compared to Bitcoin which provided a faster and more energy-efficient alternative to Bitcoin’s consensus mechanisms.