How do I add contacts to Contacts?

How do I add contacts to Contacts?

Does this do something?  I'm really confused... where do I see our organizations contacts?  And is this the only way to get access to the users that are part of the organization?  I can't seem to add anyone here and the way it looks, is that if I want to chat with someone, I have to click the + then go search them, then chat with them.