Entity-relationship analysis comprises of three major abstractions to describe data. These are entities, relationships and attributes.
Here entities are the distinct things in the enterprise. Relationship is the relation between the entities and attributes are the nature or properties of the entities.
So in a software design scenario we assimilate similar objects in sets and call these sets as entities. We then model all interactions between the objects within the entity sets by relationships or relationship sets. Relationship sets are more difficult to perceive than entity sets. We can see the entities but relationships are always underlying and we cannot see them. This makes data analysis difficult because it is necessary to create models of things that do not physically exist as single objects.
There are two major parts in entity-relationship scenario. They are Conceptual data modeling and physical data modeling.
