Metamask
We could say that Metamask are two things in one:
On the one hand, it acts as a "gateway" between our usual browser and the Ethereum blockchain, without the need to install any type of software or download the complete one of its blockchain -more than 400GB-.
All this is possible thanks to a simple extension added to our browser -Metamask-, which allows us to interact with Dapps and smart contracts in an easier and more intuitive way than we would do through Mist, the Ethereum browser.
On the other hand, this extension also functions as a wallet. It allows us to receive, send and send Ether and other ERC20 tokens from the address created in Metamask