Hi, Arjun,
Mary C. has the answer.
After you have created a resource or activity, you can hide it from students by clicking on the eye icon beside the link to it.
Your fellow teachers in the course can see it, though. It is not hidden from teachers.
After your colleague has seen the resource or activity and has approved it, you can click on the eye again to "unhide" it from students in the course.
Does that help at all?
Regards,
Art