What is Vessel?
Vessel is a desktop wallet for the Steem blockchain, which can be downloaded and run on your computer. Vessel is free to use and open source, and is designed to be a way to help secure your account. While using Vessel, your keys/password never leave the app, transactions are signed locally, then broadcast to the blockchain much like any other downloadable cryptocurrency wallet.
With Vessel, you no longer need to trust your web browser while performing secure actions with your account.