Blockchain technology is a type of distributed database or ledger that enables secure sharing of information between multiple parties in a decentralized and immutable manner. It is best known for its role in cryptocurrency systems, but it has many other applications across various industries, including supply chain management, smart contracts, cybersecurity, and internet of things (IoT).

A blockchain database stores data in blocks that are linked together chronologically to form a chain of data. Each block contains a collection of data, and once it is full, the information is run through an encryption algorithm, which creates a hexadecimal number called the hash. The hash is then entered into the following block header and encrypted with the other information in the block. This creates a series of blocks that are chained together, and the blocks confirm the exact time and sequence of transactions.

Blockchain technology has several key features, including decentralization, transparency, immutability, and security. Decentralization means that the power to update a blockchain is distributed between the nodes or participants of a public or private computer network. Transparency means that the information stored on a blockchain is visible to all participants in the network. Immutability means that once a block is added to the blockchain, it cannot be altered or deleted. Security is achieved through the use of cryptographic algorithms that ensure the integrity and authenticity of the data stored on the blockchain.

In summary, blockchain technology is a distributed database or ledger that enables secure sharing of information between multiple parties in a decentralized and immutable manner. It has several key features, including decentralization, transparency, immutability, and security, and it has many applications across various industries.