A web wallet is an online service that allows users to store, send, and receive digital currencies such as Bitcoin or Ethereum. It enables users to access their funds from any device with an internet connection, making it convenient for managing cryptocurrencies without the need for a software installation. Web wallets are accessible through web browsers and offer functionalities like balance checking, transaction history, and sending/receiving coins. It is essential to choose a reputable web wallet provider to ensure the security of your digital assets.