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Is there a difference between the terms Entity and Object?
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Entity: An entity represents a single instance of your domain object saved into the database as a record. It has some attributes that we represent as columns in our tables. Model: A model typically represents a real world object that is related to the problem or domain space.
A class is a template for an object (among other things), and is a very general concept. An entity has more semantic significance and is usually tied to a concept (possibly about a real object for example, an Employee or a Student or a Music Album) and is linked to business logic.
From an object-oriented perspective, an entity object represents an object in the real-world problem domain. From a relational database perspective, an entity object provides a Java representation of data from a database table.
In general, an entity (pronounced N-tih-tee ) is an existing or real thing. The word root is from the Latin, ens , or being, and makes a distinction between a thing's existence and its qualities.
Generally speaking, an entity is an abstract concept that's typically represented by a table in a database schema. The term object usually refers to in-memory data structures. An object that represents an entity may be called an entity object (often mapped to a row in a database table), that is it's an instance of an entity class (often mapped to a table).
In the .NET Framework (3.5 SP1) an entity is part of an instance of the EDM (Entity Data Model), and is mapped to rows in one or more tables. For example, ther can be a Customer entity type that can map to a single Customer database table or it may also extend to a CustomerPreferences table as well. Using the EntityProvider, you can access entites, as if they were just rows in database tables, using eSQL. The EDM model is also known as the conceptual layer.
There is another layer on top of the EDM model known as the object layer, where entities are materialized as EDM-mapped objects.
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An entity is something that exists in itself, actually or potentially, concretely or abstractly, physically or not. It needs not be of material existence.
In computer science, an object is a location in memory having a value and possibly referenced by an identifier.
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