Wallet
Quick definition
Software or hardware that holds the keys controlling your Bitcoin.
A wallet doesn't store coins โ those live on the blockchain. It stores and manages the private keys that control them, and gives you addresses to receive funds.
Wallets come hot (online: apps, browser extensions) and cold (offline: hardware devices), custodial (an exchange holds keys) and non-custodial (you do). Every wallet you control comes with a seed phrase โ back it up.