Metamask is a browser-based plug-in/add-in or browser extension, which allows users to carry out various Ethereum transactions
BREAKING DOWN Metamask (Cryptocurrency)
Metamask acts as a bridge between the various Ethereum interfaces and regular web browsers. For instance, an Ethereum user may transact and work on the Ethereum network using specific tools and interfaces like the Mist browser or other Dapps which require dedicated installation and configuration. In contrast, the Metamask extension is added to browsers like Chrome, Firefox, Opera, and the new Brave browser, allowing an easy to use, no-installation add-on that facilitates seamless connectivity to the Ethereum network and a faster execution of transactions.
Metamask Is A Bridge Between Various Ethereum Interfaces
Metamask essentially brings Ethereum blockchain data and transactions to a standard web browser. For instance, assume that you want to make a purchase an online shopping portal like Amazon, and wish to pay using Ethereum. To make the payment, you have to broadcast payment details on the Ethereum blockchain, from where Amazon will verify it and then process your order. This requires your PC (and Amazon’s) to work as a node on the Ethereum blockchain, and carry out various activities like broadcasting the transaction details.
MetaMask also includes a dedicated vault for secure identity, which provides an interface to manage user identities on different sites and securely sign and authenticate the blockchain transactions for each.