And what is Blockchain? Imagine a blockchain as a digital notebook that many people share. Instead of one person keeping the notebook, everyone has a copy. Whenever someone adds new information (like a transaction), it gets written down in the notebook. Once it's written, it can't be changed or erased.

just a blockchain fan from Novosibirsk. student of KIT

And everyone sees the same thing. This makes it really hard for anyone to cheat or tamper with the information. So, in short, a blockchain is like a super-secure and shared digital notebook for keeping track of stuff, like transactions, across a big network of computers.