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

That folder icon is how Github shows submodules

A submodule is essentially a reference to another repository (specifically, a specific commit in another repository)

There should be a .gitmodules file at the root of the repository, containing something like this:

$ cat .gitmodules
[submodule "ca_log_analysis"]
      path = ca_log_analysis
      url = git://github.com/example/ca_log_analysis_repo.git

You could commit your changes to that linked repository, then update the master project to look at the new commit. The Git book chapter on submodules should explain things