Blockchain technology is like the internet in that it has a built-in robustness. By storing blocks of information that are identical across its network, the blockchain cannot:
The blockchain network lives in a state of consensus, one that automatically checks in with itself every ten minutes. A kind of self-auditing ecosystem of a digital value, the network reconciles every transaction that happens in ten-minute intervals. Each group of these transactions is referred to as a “block”. Two important properties result from this:
Transparency data is embedded within the network as a whole, by definition it is public.
It cannot be corrupted altering any unit of information on the blockchain would mean using a huge amount of computing power to override the entire network.
Node:
(computer connected to the blockchain network using a client that performs the task of validating and relaying transactions) gets a copy of the Blockchain which gets downloaded automatically upon joining the blockchain network.
Together they create a powerful second-level network, a wholly different vision for how the internet can function.
Every node is an “administrator” of the blockchain, and joins the network voluntarily (in this sense, the network is decentralized). However, each one has an incentive for participating in the network: the chance of winning Bitcoins.
Nodes are said to be “mining” Bitcoin, but the term is something of a misnomer. In fact, each one is competing to win Bitcoins by solving computational puzzles. Bitcoin was the raison d’etre of the blockchain as it was originally conceived. It’s now recognized to be only the first of many potential applications of the technology.