Blockchain is the technology that sits behind a new kind of database called a distributed ledger.
It gives us a much more secure way to store and manage data.
Data is shared across a network, and everyone in the network has an identical copy of it.
If anyone changes the data, it shows up in all the copies within minutes or even seconds.
That makes it more difficult to attack a blockchain database than a single one, where the data is all in one place.