It's hard man, I guess it's like trying to explain to my mom about blockchain. So, let me see if I can explain as easy as I can

I could say that blockchain is an accounting record of digital currency (called cryptocurrencies) transactions. This digital ledger is replicated on millions of computers all over the internet. This makes it indestructible, reliable, and perennial.

Initially, the blockchain was created to keep track of cryptocurrencies, however, today the blockchain not only saves transaction records but also all kinds of information. Making it a secure means to save and maintain untouchable information in a perpetual way.

Maybe these fellows could help you better ^_^