There are three types of data models – conceptual, logical and physical. The level of complexity and detail increases from conceptual to logical to a physical data model.

The conceptual model shows a very basic high level of design while the physical data model shows a very detailed view of design.

The conceptual model will be just portraying entity names and entity relationships. Figure 1 shown in the later part of this article depicts a conceptual model.

The logical model will be showing up entity names, entity relationships, attributes, primary keys and foreign keys in each entity. Figure 2 shown inside question#4 in this article depicts a logical model.

The physical data model will be showing primary keys, foreign keys, table names, column names and column data types. This view actually elaborates how the model will be actually implemented in the database.