This is where wallets come in.
The primary function of Bitcoin wallets is to keep track of your identity.
Unlike how we use physical wallets to conveniently hold onto and store our physical money, our digital Bitcoin wallets don’t actually let us store bitcoins.
Bitcoin wallets are simply a method of storing and accessing your private key, which then allows you to spend the corresponding bitcoin.
Most wallet software will also store, send, receive, and list transactions for you, since it’s easy for software to do this but not necessarily for humans.
It would be infeasible to manually keep track of all blockchain activity involving you.
To take care of this, wallet software will store all relevant information about the blockchain on your behalf.