Bitcoin is run on a system that's unique called the Blockchain. I'll explain "blockchain" in a manner that is easy to understand before you tune in.

Imagine a public book where all Bitcoin transactions are recorded. This notebook records every Bitcoin transaction.

This notebook is transparent, so everyone can see what's in it. However, no one can alter it.

The blockchain is the name of this notebook. This notebook keeps Bitcoin safe and secure, ensuring that no one can spend the same Bitcoin twice.