What does green folder icon in github web interface mean?

Question

I wanted to add some folder in my current git repo.

but i have received such green folder in the github the following image . How to add this folder into this project.<

Answer 1

I believe the green folders represent submodules on github. A submodule is essentially a link to a version of another repo.

To get the submodules locally run:

git submodule init
git submodule update

You can read more about submodules here: http://git-scm.com/book/en/Git-Tools-Submodules