A wallet is a software program that stores your private key (or seed phrase) and interacts with the blockchain to give you access to your ETH balance. It also allows you to send ETH to other addresses.
Most wallets also let you view your past transaction history and some have built-in exchanges that let you buy and sell ETH directly from the wallet interface.
There are many different types of wallets, but they all essentially work in the same way. Some wallets are designed for specific cryptocurrency platforms like Ethereum, while others can be used for multiple cryptocurrencies.
The most important thing to remember when choosing a wallet is to make sure it supports the cryptocurrency you want to use it for. You should also consider things like ease of use, security features, and whether or not the wallet offers additional features like a built-in exchange.
No matter which wallet you choose, always remember to keep your private keys safe and never share them with anyone else.