Self-custody in plain English
When your Bitcoin sits on an exchange, you own an IOU. The exchange holds the keys. If it gets hacked, freezes withdrawals or goes bust, you wait in line with everyone else.
Self-custody means you hold the keys yourself, usually in a hardware wallet. Start small: buy a reputable hardware wallet direct from the maker, write the recovery words on paper, store them somewhere safe and never type them into a website or share them with anyone. Then send a small test amount before moving more.