The main thing to understand about this technique is that a data model visually represents the aspects that are of significance to the business (for example, the people, places, and things). It describes the attributes associated with those aspects and shows the most important relationships between them. 

There are three variations of data models to understand:

• A conceptual data model: This type of model is independent of any technology or solution and is intended to depict the way a business perceives information.
• A logical data model: This type of model is another interpretation of a conceptual model with the addition of showing data entities and their relationships. It also shows rules of normalization. 
• A physical data model: This type of model is the actual depiction of how data is physically implemented in the form of a database. It also considers factors such as performance, concurrency, and security.