Grunt-cli and Grunt - Same app, two versions?

Question

Achtung!

The accepted answer answered my question at the time, but is now outdated. Back then grunt-cli used grunt, but with another branch. The not-accepted answers

Answer 1

From: http://gruntjs.com/getting-started

Install grunt-cli just will put the grunt command in your system path, allowing it to be run from any directory.

Even more:

...Installing grunt-cli does not install the Grunt task runner! The job of the Grunt CLI is simple: run the version of Grunt which has been installed next to a Gruntfile. This allows multiple versions of Grunt to be installed on the same machine simultaneously.