How does Bitcoin work?

Explain how Bitcoin works.
The astonishing math behind it's encryption.

0:00 - Introduction
2:25 - Ledgers and digital signatures
7:21 - The ledger is the currency
10:06 - Decentralization
12:26 - Cryptographic hash functions
14:38 - Proof of work and blockchains
19:42 - Double spending
21:41 - Block times, halvenings, and transaction fees
24:40 - Thanks