Cryptocurrency is a type of digital currency which uses encryption methodologies to adjust the formation of units of currency and verifying fund transfers that are operated independently without any authority involved as medium.
These cryptocurrencies are decentralized and completely away from any authority that is governing the real money. Though digital currencies have multiple usage, now-a-day these currencies are often utilized in crowdsale i.e. funds raised by startups for a cause in the form of Initial Coin Offering.
If you take away all the noise around cryptocurrencies and reduce it to a simple definition, you find it to be just limited entries in a database no one can change without fulfilling specific conditions. This may seem ordinary, but, believe it or not: this is exactly how you can define a currency.