A blockchain is – first and foremost – a digital directory of transactions, a kind of modern ledger that can be used for all kinds of purposes (not just for crypto currencies like Bitcoin). Individual entries/blocks are joined together like links in a chain (hence the name of the technology). Every transaction/change in the chain is checked and validated by a (substantial) number of other computers in a peer-to-peer network. The idea is to create a safe, distributed database for parties who don't know each other or don't trust each other or can't come up with an official admin – or all of the above. There are different types of blockchains, and there are also different types of distributed/digital ledgers (DLTs). The opposite of a blockchain (or a DLT) is a regular, centralized database. In media tech, blockchain tech is often used to solve IP challenges ("how can we access content in a smart way and make sure creators get paid for it?") and verification issues ("how can we prove this content is legit and has not been tampered with"?).