What is Metamask?
Crypto Glossary Definition
A popular ETH wallet that can be downloaded as a chrome extension or a smartphone app. It has over 20 million users, and has introduced token swapping within the wallet itself.
Why Metamask Matters
MetaMask is the most widely used browser/mobile wallet for interacting with Ethereum and EVM-compatible chains, acting as the bridge between a user's private keys and DeFi apps, NFT marketplaces, and DEXs. Because it's software (not a hardware wallet), funds held in it are more exposed to malware or phishing on the device it runs on.
Metamask in Practice
A user new to DeFi installs MetaMask as a browser extension, generates a new wallet, and is shown a twelve-word secret recovery phrase with an urgent warning to write it down and never share it. She funds the wallet by sending ETH from a centralized exchange to her new MetaMask address, then visits a decentralized exchange, clicking "Connect Wallet" and approving the connection request that pops up. From there, MetaMask acts as the signing tool for everything she does on-chain: swapping tokens, approving a smart contract to spend a specific token on her behalf, or bidding on an NFT, each action triggering a MetaMask popup asking her to review and confirm the transaction details and gas fee before it's signed and broadcast. Months later, she receives an email claiming to be from MetaMask support asking her to "verify" her recovery phrase on a linked website — a classic phishing attempt, since no legitimate wallet provider will ever ask for that phrase. Because MetaMask is a software (or "hot") wallet running on an internet-connected device, its convenience comes with a tradeoff: if malware on her computer or a phishing site tricks her into revealing that seed phrase, an attacker gains full control of every asset in the wallet, which is why many users pair MetaMask with a hardware wallet for larger holdings.
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