Magit is a text-based Git user interface that puts an unmatched focus on streamlining workflows. Commands are invoked using short mnemonic key sequences that take the cursor’s position in the highly actionable interface into account to provide context-sensitive behavior.
With Magit you can do nearly everything that you can do when using Git on the command-line, but at greater speed and while taking advantage of advanced features that previously seemed too daunting to use on a daily basis. Many users will find that by using Magit they can become more effective Git user.
Source: Magit 3.0 released, an article by Jonas Bernoulli.