Certainly it is something difficult to explain in such a short time to someone who does not know about the subject. One could say that it is the technology behind cryptocurrency, since many times it is the term with which it is most associated. That this is a system of distributed data by means of which a list of online transactions is recorded through cryptographic processes, i.e. encrypted. It is like a coded book ledger.
Just as in a ledger the operations are recorded in the pages, the transactions made in this platform are stored in a set of data called blocks, that is, permanent files with data from the network. And so, just as when new information is written on a page of the book, a block is also created, only this information cannot be changed afterwards. And the blocks form a chain because each one has a time stamp that links it to the previous one and then links it to the next one. That is, it's one page after another.
What makes this ledger special, is precisely that way of storing data. Because instead of storing the whole book in a single entity, call it a bank, each page is distributed in a network of computers around the world connected to this platform.
I hope this makes some sense to a newbie.
Greetings friend @crypto.piotr
Love your explanation @emiliomoron :)