It's a new era for technology.
The Internet has connected us on a global scale, but it has not truly linked the systems built on the Internet protocol. Imagine a technology where such systems can interoperate and any participants in such systems can liaise with each other in real-time with no need to worry about corruption or fraud in the system.
In essence, that is what the blockchain technology is: a distributed, decentralised immutable ledger which works through peer-to-peer connections allowing all users to transmit data to each other in a secure, encrypted manner and with full oversight and transparency over what is happening on the blockchain to ensure that no one cheats the system.
This technology was successfully pioneered by Bitcoin, which can essentially be seen as the first real use-case for blockchain technology.