Cryptocurrencies are the tokens that are the reward for the specific blockchain network that is being used. There are two separate classes of currencies, those that are specifically used as a store of value and those that have a utility aspect to them as well. There are over 1,000 cryptocurrencies out and those that are not Bitcoin are referred to as ALTCoins, Alternative to Bitcoin. You can go here to find a list of all the cryptocurrencies. The two different classes and some of the coins are detailed below.
There are coins that are specifically used as a store of value for transactions such as Bitcoin, Litecoin, and DASH. There are many more out there that are used for a store of value but the three highlighted are explained a little below.
Bitcoin was the first cryptocurrency, or digital cash, and uses peer-to-peer technology to operate with no central authority or banks; managing transactions and the issuing of bitcoins is carried out collectively by the network. Bitcoin is open-source; its design is public, nobody owns or controls Bitcoin and everyone can take part. Through many of its unique properties, Bitcoin allows exciting uses that could not be covered by any previous payment system. You can find more about Bitcoin here. Since August 1, 2017 there was a chain fork/split from the original chain that created Bitcoin Cash. Some people have listed this as BCC and others have it listed as BCH. You can find more information about Bitcoin Cash here.
Litecoin was published shortly after Bitcoin. Litecoin is a peer-to-peer Internet currency that enables instant, near-zero cost payments to anyone in the world. Litecoin is an open source, global payment network that is fully decentralized without any central authorities. Mathematics secures the network and empowers individuals to control their own finances. Litecoin features faster transaction confirmation times and improved storage efficiency than the leading math-based currency. With substantial industry support, trade volume and liquidity, Litecoin is a proven medium of commerce complementary to Bitcoin. You can find out more about Litecoin here.
DASH, or Digital cASH, started out as Darkcoin. Since then it has evolved to what it is now and have moved away from the Darkcoin name to DASH to help to not associate with the Darknets more mischievous actors. DASH has claimed to be a competitor to Bitcoin. You can find more about DASH here.
There are some cryptocurrencies that also have a utility aspect to them, since they are tied to coding individuals and/or teams can use them for just more than a store of value. Some examples of them are below.
Ethereum is a decentralized platform that runs smart contracts: applications that run exactly as programmed without any possibility of downtime, censorship, fraud or third party interference. These apps run on a custom built blockchain, an enormously powerful shared global infrastructure that can move value around and represent the ownership of property. This enables developers to create markets, store registries of debts or promises, move funds in accordance with instructions given long in the past (like a will or a futures contract) and many other things that have not been invented yet, all without a middle man or counterparty risk. You can find more about Ethereum here.
Gridcoin is a decentralized, open source math-based digital asset (cryptocurrency) which performs transactions peer-to-peer cryptographically without the need for a central issuing authority.Gridcoin securely rewards volunteer distributed computing performed upon the BOINC platform in a decentralized manner on top of proof of stake. Projects range from attempting to cure diseases to searching for extraterrestrial life! You can distribute virtually any kind of distributed computing process through BOINC (utilizing GPU/CPU/Sensors/etc). You can find more about Gridcoin here.
Augur is a prediction market platform that rewards you for correctly predicting future real-world event. You can find more about Augur here.