The term Blockchain typically describes a decentralized, transparent, public ledger that allows units of value to be transferred securely using public key encryption and proof-of-work technology.
Broadly speaking, it is a database shared across a network of computers. In this database, each block in the chain contains a certain number of transactions and whenever a new transaction is performed on the Blockchain, a record of this transaction is added to the ledger of each participant in the network.
This decentralised database, which is managed by various network participants, is known as Distributed Ledger Technology (DLT).
By using decentralised consensus to maintain the network, Blockchain technology has a huge advantage over traditional digital databases. It cannot be censored, manipulated or controlled by a single centralised network participant, institution or government.