Bitcoin itself, in a nutshell, is either virtual currency or referencing the technology, depending upon who you talk to. Some very interesting things happen with a Bitcoin transaction:

• It is irreversible, period.
• It is pseudonymous. Nothing is related to any real-world identity.
• It's fast and global. Transactions are confirmed in just a few minutes, regardless of physical location.
• It's secure. Since Bitcoin money is locked in a cryptography system, only the owner of the private key can send currency.
• You need no permissions.

If you are not familiar with this technology, and perhaps actually do live under that proverbial rock, let me explain why you should not worry too much about the safety of your money. Just remember, it's virtual, so could something go wrong, sure. But think about this.

You go into a store to make a purchase. You use your credit card to pay. There's no signature on the back. You sign the receipt. You walk out with your purchase. Did that make you feel safe? How much effort did the cashier really put into verifying that it's you? But you don't worry, because you have nobody-paid-attention insurance from your major credit card. You can dispute it any time. But wasn't that all virtual as well? You just trusted someone you've never met with your finances.

The blockchain, and Bitcoin, use a peer-to-peer decentralized system to conduct transactions. They employ asymmetric cryptography using elliptical curves to make transactions secure, and one of the keys is digital signatures.