I am Designing an ERD Diagram, and I am getting too much confused by this because first of all I have not developed an Entity Relationship Diagram, since I was in second semester, and secondly I have totally forgot how to create it, what rules are kept in mind while creating it, and what are the shapes to be drawn, therefore I am getting help from Internet but I am unable to get things fast so I think I have to study it deeply for Better understanding . Also I am going to get help my Boss

Image is from Link