Entity relationship modelling refers to the design and creation of a diagram, called an entity-relationship (ER) diagram, which is a graphical representation of entities and their relationships to each other,
In database design, Entity-relationship (ER) diagrams are used to model the organization of information within a database.
But they also have application in modeling the relationships between people, places or events
|And they can be used to model the relationships of things like the pages of this site.|
In an Entity-relationship (ER) diagram, An entity is an object or concept (typically represented as a standard shape) and the relationships between them are reoresented by lines. The relationships may be directed, as in project management in which case arrow heads are used.
They may also indicate particular types of relationships as in database design where, in relational databases. conditions like ‘one to many’ are common and there are standard symbols for this as well. In Object oriented databases, the relationships between objects is more sophisticated and the ER diagram, more complex