What is Blockchain?

Blockchain is a type of database that stores data in blocks.  When a new block fills up, it will be chained to the original data.  Blockchain primarily refers to the how the database is structured.  The other part of blockchain is its ability to be decentralized.  The main use of blockchain so far has been the use of distributed ledgers.  In the case of Bitcoin, the ledger is a permanent archive of every transaction that has ever occurred on the Bitcoin blockchain.  Bitcoin nodes have the entire chain stored on them.  As of today, the blockchain for Bitcoin is 334 GB and from a quick glance seems to grow a gig every couple of days.  For a comparison, the Monero blockchain is only about 120 GB.  Blockchain technology can be used for games and virtual worlds.  It can be used for creating tokens that represent real and intangible property.  There are many uses and I am sure many more will be discovered as time goes on.  The beauty of the blockchain is that no one entity can bring it down.  It is decentralized and stored on thousand upon thousands of random computers distributed worldwide.  Not one country or one company controls Bitcoin or its blockchain.  It is there for everybody to use equally.