Manual testing is the process of manually testing software for any and all defects that it may have. It requires a tester who is well equipped in the field to play the role of a user and use most of the features of the application to ensure correct behavior. If you take any courses to know exactly how to do this properly, you will be most likely to get a job at a better place than without it. It will do your career good to take courses in this area. Find your QA guru and start your manual testing training now!