Bitcoin (BTC) is a digital currency. As Bitcoins don’t exist in any physical shape or form, they can’t technically be stored anywhere. Instead, it’s the private keys — which are used to access your public Bitcoin address and transaction signatures — that need to be securely stored. A combination of the recipient’s public key and your private key is what makes a Bitcoin transaction possible.
There are several different forms of Bitcoin wallets that cater to different requirements and vary in terms of security, convenience, accessibility and so on..