A way simple to understand what is blockchain.

Let’s try to understand what is blockchain technology with a simple real-life example.
There are four friends living in a hostel. They used to go for dinner every night and one of them pay the entire bill of the dinner.
He pays the bill throughout the week and writes down all the expenses in a register.
But there is an issue. The issue of trust. Maybe he writes it down incorrectly by mistake. They have another solution to solve the issue. All they need is to buy 4 copies and give to 1 copy to everyone.
Whenever they go for the dinner, everyone is required to write down the expenses in his own copy. Yes, it is a time-consuming process but in the end, you will get an efficient storage of data and everyone will be satisfied.
The blockchain technology works in a similar way. The data is stored in blocks and the blocks are distributed all over the network.