Blockchain isn’t an entirely new technology. Instead, it combines several existing technologies, such as asymmetric cryptography, timestamp and consensus, etc.
Take Bitcoin for instance, it uses timestamps and Proof-of-Work system to prevent Double Spending and solving the Byzantine Generals’ Problem, ensuring that no Bitcoin can be spent twice and transactions across all nodes in the decentralized network remain consistent.
Asymmetric cryptography ensures the safety of private keys. Timestamp connects the blocks in chronological order. Proof-of-work mechanism solves the problem of distributing the 21 million Bitcoins fairly in a decentralized environment.
Blockchain technology is anonymous, decentralized and transparent. Therefore, it’s been referred to as “the trust machine”.