Blockchain is a secure process for online transactions, a digital shared ledger technology.
Blockchains store information across a network of personal computers, making them decentralized and distributed, ensuring no central company nor person owns the system, yet everyone can use it. This ensures no one can take down the system, hack or corrupt the system or chain. When you use the system your computer becomes a node. Bundles of records, known as 'blocks' are submitted by others in a chronological chain using crypto-graphy, a form of math used to ensure records can't be changed nor counterfeited by any node.
Digital currency is an example of using blockchain technology. There is no bank, nor financial middle man involved. Instead, people all over the world help move the digital currency by validating transactions with their personal computers earning digital currency (blocks) in the process, called mining. Digital currency uses blockchain by tracking records of ownership, so only one person can be an owner at a time, of a specific digital currency, and can't be spent twice.
It takes at least six blocks to validate a transaction (minimal is approximately an hour). These blocks make up the chain, hence the word 'blockchain.' There are currently over 5,600 nodes (52.5 Gigs) worldwide and doubling annually. The record of transactions are irreversible, in-erasable and transparent.
Blockchain contains a two-part process, a keyhole and a key (the blocks making up the keyhole). Only the receiver has the key.
You begin with your own wallet of digital currency and, as an example, let's say you want to send an amount of it to someone else. When you send the transaction to a receive, the receiver is the only one with the key to be able to receive (open) the block of information (transaction). After the blocks have been verified by the other nodes (the chain) in the system, showing all stakeholders the movement of the asset from A to B), the key is able to receive (open) the validated transaction (keyhole 'blockchain'). The transaction gets updated across the system to all other nodes. This maintains consensus and security across the network system.
Mining is considered 'proof of work' and a way to earn additional digital currency (blocks). Along with confirming the information in the block, each block has a unique math problem to solve, which the miner performs to fully validate the block. When this node solves a math problem in a block, they get a new block for them self ('mining'), and updates the block.
The future of exchange is evolving towards a more equivalent, transparent, secure exchange. Usury and middle men are eliminated by using block- chain. There are many other uses for blockchain technology, you will enjoy doing your own research and discovering the vast possibilities this technology provides, evolving humanity towards a thriving world, working for all, facilitating a transition, for good!