Bitcoin is a peer-to-peer electronic cash system that is entirely virtual and can be stored in a Bitcoin wallet. Bitcoin wallet stores the information of your Bitcoin, such as the Bitcoin address (like your bank account number), and your private key (like the pin code for your ATM card).
Like how our physical wallets can contain multiple bank cards, Bitcoin wallets can store multiple Bitcoin addresses as well and the corresponding private keys to each Bitcoin address. The core function of a Bitcoin wallet is to protect your private key. If you lose the wallet, those Bitcoins will be gone for good.
Bitcoin wallets come in numerous forms such as PC or smartphone wallet clients, web wallets, Or even writing down your private key, In a notebook (paper wallet) or memorizing it (brain wallet). You can choose the right wallet based on your needs.
Don’t put all your eggs in one basket, store your Bitcoins in different places to reduce the risks!