Fellows, I've been trying to find a good way to explain Bitcoin's functioning logic to people that are not familiarized with this technology, and I'd like to hear from you guys: if you had the task of explaining BTC to someone, what concepts would you highlight the most?

It is Decentralised implying:
1. that you get the tasks (transactions) done yourself and do not need anyone or agent to approve it before it's been confirmed. Thus making you, your own boss.
2. It cannot be hacked since no central system is available to be attacked.