An Entity Relationship Model, also known as an Entity Relationship Diagram, a graphical representation of entities and their relationships to each other, typically used in computing in regard to the organization of data within databases or information systems. An entity is a piece of data; an object or concept about which data is stored. A relationship is how the data is shared between entities. The three types of relationships between entities are one-to-one, one-to-many, and many-to-many.
One-to-one is when one instance of an entity A is associated with one other instance of another entity B.
One-to-many is when one instance of an entity A is associated with zero, one or many instances of another entity B, but for one instance of entity B there is only one instance of entity A.
Many-to-many is when one instance of an entity A is associated with one, zero or many instances of another entity B, and one instance of entity B is associated with one, zero or many instances of entity A.
A Semantic Object Model is developed from objects that are already known. This model is normally used to document a system, program, or object that is already in use and working properly. Another term for Semantic Model from the field of knowledge representation is “ontology”: the set of classes, relationships, and functions in a universe of discourse.
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Entity-Relationship model vs. Semantic Object model. (2016, Jul 02). Retrieved from https://studymoose.com/entity-relationship-model-vs-semantic-object-model-essay