How does the Blockchain Work (for Dummies) explained simply
What’s under the blockchain hood?Blockchain is a type of distributed ledger or decentralized database that keeps records of digital transactions. Rather than having a central administrator like a traditional database, (think banks, governments & accountants), a distributed ledger has a network of replicated databases, synchronized via the internet and visible to anyone within the network. Blockchain networks can be private with restricted membership similar to an intranet, or public, like the Internet, accessible to any person in the world.
When a digital transaction is carried out, it is grouped together in a cryptographically protected block with other transactions that have occurred in the last 10 minutes and sent out to the entire network. Miners (members in the network with high levels of computing power) then compete to validate the transactions by solving coded complex problems. The first miner to solve the problems and validate the block receives a reward. (In the Bitcoin Blockchain network, for example, a miner would receive Bitcoins).
The validated block of transactions is then timestamped and added to a chain in a linear, chronological order. New blocks of validated transactions are linked to older blocks, making a chain of blocks that show every transaction made in the history of that blockchain. The entire chain is continually updated so that every ledger in the network is the same, giving each member the ability to prove who owns what at any given time.
“A blockchain is a magic computer that anyone can upload programs to and leave the programs to self-execute, where the current and all previous states of every program are always publicly visible, and which carries a very strong crypto economically secured guarantee that programs running on the chain will continue to execute in exactly the way that the blockchain protocol specifies.” — Vitalik Buterin
Blockchain’s decentralized, open & cryptographic nature allow people to trust each other and transact peer to peer, making the need for intermediaries obsolete. This also brings unprecedented security benefits. Hacking attacks that commonly impact large centralized intermediaries like banks would be virtually impossible to pull off on the blockchain. For example — if someone wanted to hack into a particular block in a blockchain, a hacker would not only need to hack into that specific block, but all of the proceeding blocks going back the entire history of that blockchain. And they would need to do it on every ledger in the network, which could be millions, simultaneously.