Blockchain is a piece of software designed to create decentralized databases.
The system is completely "open source", which means that anyone is able to view, edit and propose adjustments to its underlying code base.
Whilst it has turn out to be more and more common thanks to Bitcoin's progress - it's truly been around since 2008, making it round a decade old (historical in computing terms).
Crucial level about "blockchain" is that it was designed to create functions that do not require a central information processing service. This implies that in the event you're using a system build on top of it (namely Bitcoin) - your data can be stored on 1,000's of "independent" servers around the globe (not owned by any central service).
The way in which the service works is by making a "ledger". This ledger allows users to create "transactions" with one another - having the contents of these transactions stored in new "blocks" of each "blockchain" database.
Relying on the appliance creating the transactions, they need to be encrypted with different algorithms. Because this encryption makes use of cryptography to "scramble" the data stored in every new "block", the term "crypto" describes the process of cryptographically securing any new blockchain knowledge that an utility may create.
To fully understand how it works, you need to respect that "blockchain" shouldn't be new technology - it just uses technology in a slightly totally different way. The core of it's a information graph generally known as "merkle timber". Merkle trees are essentially ways for pc systems to store chronologically ordered "versions" of a knowledge-set, allowing them to manage continuous upgrades to that data.
The reason this is necessary is because present "information" systems are what could possibly be described as "2D" - meaning they have no strategy to track updates to the core dataset. The info is basically kept completely as it is - with any updates applied directly to it. Whilst there's nothing mistaken with this, it does pose a problem in that it signifies that data either has to be up to date manually, or his very troublesome to update.
The answer that "blockchain" supplies is actually the creation of "variations" of the data. Each "block" added to a "chain" (a "chain" being a database) gives a list of new transactions for that data. This signifies that in the event you're able to tie this functionality into a system which facilitates the transaction of data between or more users (messaging and so forth), you'll be able to create a wholly unbiased system.
This is what is blockchain
we've seen with the likes of Bitcoin. Contrary to fashionable perception, Bitcoin isn't a "currency" in itself; it is a public ledger of economic transactions.
This public ledger is encrypted so that solely the participants within the transactions are able to see/edit the data (hence the name "crypto")... however more so, the fact that the data is stored-on, and processed-by 1,000's of servers all over the world means the service can operate independently of any banks (its important draw).
Clearly, issues with Bitcoin's underlying idea and many others aside, the underpin of the service is that it's basically a system that works throughout a network of processing machines (called "miners"). These are all running the "blockchain" software - and work to "compile" new transactions into "blocks" that retains the Bitcoin database as up to date as possible.