The ERD (Entity Relationship Diagram) is a diagram which contains entities represented by rectangles, attributes represented by ovals connected to the rectangles, and rhombus showing the relationship between each entity......the entity is actually the names of the tables or relations of your database and the attributes are the names of the fields or columns in those tables....one of those attributes may be underlined which means it is the primary key of that relation (table).
Example:
In this ERD....Patient and Doctor will be the names of the tables in your database
the Patient table consists of ( Patient-ID, Patient-Name, Patient-Age) fields or columns..while the Doctor table has ( Doctor-Name, Speciality, Experience-Years, Physical-ID) and the relationship between them is ( Primary-Physician )
Hope that was your question :)
Example:
In this ERD....Patient and Doctor will be the names of the tables in your database
the Patient table consists of ( Patient-ID, Patient-Name, Patient-Age) fields or columns..while the Doctor table has ( Doctor-Name, Speciality, Experience-Years, Physical-ID) and the relationship between them is ( Primary-Physician )
Hope that was your question :)