This article explains the subject in simple terms, please be aware some technical inaccuracies may occur :
Blockchain is a way to solve a problem, the double spending problem. How does it solve it?
It uses a group of miners that are competing between themselves to solve a “mathematical” problem.
The first to solve this problem gets to register a block of transactions on the ledger, while getting paid for his efforts.
There is mathematical evidence that the longer the chain is, or the more blocks are registered,
it makes it less probable for miners to be able to write…