A concept is a key idea that is both basic and critical to your audience. “Basic” means this term is probably mentioned many times a day in conversations with the people who are the audience for the model. “Critical” means the business would be very different or non-existent without this concept.
The majority of concepts are easy to identify and include concepts that are common across industries, such as Customer, Employee, and Product. An airline may call a Customer a Passenger, and a hospital may call a Customer a Patient, but in general they are all people who receive goods or services. Each concept will be shown in much more detail at the logical and physical phases of design. For example, the Customer