In your “bitcoin wallet,” of course...
Once you have acquired bitcoin, you will want to make sure that you store it in a secure fashion that suits your taste and needs. You have several options for this, since technically all you’re storing is a few lines of code, and this can be done on a computer, in a cloud, on a removable storage device, or on some sort of physical medium such as paper or even a physical manufactured bitcoin.
There are many bitcoin wallet apps and services are out there, with which a user can store and transact their bitcoin-friendly business from the comfort of their own phones. These are also known as “hot” wallets. Taking one’s bitcoin off the grid and choosing to secure it in a manner that is not connected to the web (generally) or ready to transact is referred to as keeping bitcoin in cold storage, or a “cold” wallet.
Cold wallets can be on USB sticks or other devices which can be carried on one’s person or stored in a safe place and may include extra layers of security to protect your personal key. A bitcoin user’s personal key is what permits bitcoin to flow out of the account as a push transaction. In all forms of bitcoin wallet, care should be taken to safeguard the personal key of the user.
Many wallets implement two-factor authentication (sometimes called 2FA), requiring that the bearer of the wallet use a pin number or fingerprint, or respond to a text sent to their phone, in addition to possessing the drive which contains the personal key. Recently it has become possible to deposit bitcoin on ‘Bitpay Debit Cards’ that are accepted everywhere that Visa debit cards are accepted.