The Free On-line Dictionary of Computing (19 January 2023):

entity-relationship model

    The most common kind of data
   modelling, proposed by Peter P. Chen in 1976, in which a
   database is divided into "entities" and "relations".

   Part of capturing the requirements of an application is
   defining the entities involved and their relationships.
   Together, these form an entity-relationship model.

   Entities are the kinds of things or concepts the application
   deals with, e.g. products, customers, sales transactions.  A
   relationship connects two entities and says how many instances
   of each participate in the relationship - one-to-one,
   one-to-many or many-to-many.

   Entities and some relationships correspond to database
   tables.  A table corresponding to a relationship is also
   known as a "join table" after the join database operation.

   A model is represented graphically as an entity-relationship
   diagram.

   ["The entity-relationship model: toward a unified view of
   data", P.P. Chen, ACM Transactions on Database Systems 1:1 pp
   9-36, 1976].

   (2019-11-03)