Imagine buying something and paying for it online without having to go through a bank or a credit card agency. This is what cryptocurrency allows you to do. It is a virtual currency that can be sent and received securely without any personal information attached to it. Your information isn’t included in the transactions and the coins can be sent/received anywhere to/from anyone (details here). A few things that differentiate cryptocurrency from cash/credit is that each coin is valued the same across the world, there is a finite supply of Bitcoin (21 Million), and it is much more durable since it is all held online. With cash, it's possible to lose it or accidentally destroy it, but with cryptocurrency, this isn't common. The only ways to really "lose" your cryptocurrency is to save your coins in a paper wallet (offline storage) and misplace that or to forget your username/password to your exchange (which should be retrievable).