Altcoin is a combination of two words: “alt" and "coin"; alt is short for alternative and coin signifies currency. Thus together they imply a category of cryptocurrency that is alternative to the digital currency Bitcoin.  Examples of these coins may include Ethereum, Litecoin, Dogecoin, Peercoin, Feathercoin, Zetacoin, Novacoin.

Altcoins are generally more volatile than Bitcoin and there can be massive shifts in their value based on market perception.

They are all newer than Bitcoin, ranging from a few years old (after 2010) to a few days old.

Altcoins have their own communities built around them.  These communities are made up of people that have an intrinsic interest in the coin and will find ways to support the coin.

Altcoins also have their features.  Generally speaking, Altcoins are deviations from the original Bitcoin technology with perceived enhancements or differentiations to bring them alternative value.  Newer and more innovative versions are getting launched that offer modifications in areas like transaction speed, privacy, proof-of-stake, DNS resolution and more.

They are also highly tradable and investable.  People are all looking for the new Bitcoin.

To illustrate different examples of Altcoins, the section below provides more detail on some of the more notable Altcoins.