A blockchain is a distributed ledger, similar to a database, but rather than being controlled by a central authority such as big corporations, small businesses, or individuals, the ledger is dispersed across multiple computers, which can be located all over the world and run by anyone with an Internet connection. At its core, a blockchain is a ledger into which data is added and updated in real-time via consensus of the different nodes running the software in the network.
Each block that stores a certain amount of data is linked by chains sequentially based on the time they were created. These chains are stored in all the servers in the network, which means as long as there is at least one server up and running, the whole blockchain is secure. These servers, known as nodes, offer storage and computing capacity to the blockchain. Tampering with the data in a blockchain is extremely difficult, as it requires the consent of more than half of the nodes, which are in the control of different entities, to change the information in every node.
Blockchain boasts two distinct advantages over traditional networks—they are tamper-proof and decentralized. The combination of the two edges is beneficial in removing trust issues between people by enhancing the credibility of the information recorded in the blockchain.
The blockchain technology is now mainly used to issue digital currencies, but its use cases go way beyond that. Since the advent of Bitcoin, the use of blockchains has been expanded to a new level. Instead of being confined to dealing with financial data, blockchains have been used by many projects as a medium to store and validate all sorts of data, including that from social media applications and games.