1. Wallet Functionality: MetaMask allows users to create and manage Ethereum wallets, enabling them to send, receive, and store Ether (ETH) and ERC-20 tokens.
2. Browser Extension: MetaMask is available as a browser extension for popular web browsers like Chrome, Firefox, Brave, and Edge. Users can easily add the extension to their browser, creating a convenient way to access decentralized applications.
3. DApp Interaction: MetaMask acts as a bridge between web browsers and Ethereum-based DApps. When users encounter a decentralized application that requires interaction with the Ethereum blockchain, MetaMask prompts them to connect their wallet to the application.
4. Security: MetaMask emphasizes security and privacy. Users are required to set up a password during the initial wallet creation, and they are provided with a 12-word seed phrase (mnemonic phrase) that serves as a backup to recover the wallet if needed.
5. Token Support: In addition to Ether, MetaMask supports a wide range of ERC-20 tokens. Users can add custom tokens to their wallet by providing the contract address.
6. Networks: MetaMask supports multiple Ethereum networks, allowing users to switch between the Ethereum mainnet, testnets (such as Ropsten, Rinkeby, and Kovan), and custom networks.
7. Updates: MetaMask regularly releases updates to improve functionality, security, and user experience. Users should ensure that they are using the latest version of the extension.

Please note that developments may have occurred since my last update in January 2022, and it's advisable to check the official MetaMask website or other reliable sources for the most current information and features.