Blockchain Vs. Database
A Blockchain is a database or a ledger that stores information in a data structure called blocks. It is based on distributed ledger technology which can be used between parties that don't trust each other with data. It is so because adding something to blockchain requires verification from other users.
A blockchain keeps information permanently in uniform sized blocks. Each block stores the hashed information from the previous block to provide cryptographic security. The blockchain hashing uses SHA256 which is a one-way hash function. The hashes of previous blocks that goes all the way back to the very first block produced in the blockchain called a "genesis block." A blockchain data structure is in the form of a Merkle Tree, which is used as an efficient way to verify data.
A database is a kind of central ledger where the administrator manages everything. Here the administrator provides rights to read, write, update, or delete operation. Since it is centralized in nature, their maintenance is easy, and output is high. But it also has a drawback which when corrupted can compromise the entire data and can even change the ownership of digital records.
A database uses a client-server network architecture. Here database administrator has rights to make changes in any part of the data and its structure.