I'll try to explain it to you using layman terms as much as possible. To those who will reply after me, just correct me if I am wrong. For now, Let's just say that blockchain in a sense is like a digital logbook which is always distributing information. That information (which is a data about a transaction) is always being broadcasted to a network of computers who validates it. Take note that those computers validating the transaction is not owned by a single entity or group, it is owned by many people in the community and the owners of those computers are called miners. After they validated the information, that verified data(which is permanent and cannot be altered by anyone) will be added to the existing data in the blockchain(the digital logbook) and will be stored on those network of computers. That's how blockchain works.