As mentioned in other areas of this site, the database life cycle (DBLC) consists of five stages:

1. Requirements Analysis
2. Logical Design
3. Physical Design
4. Implementation
5. Monitoring, Modification, and Maintenance

In the first stage of the DBLC, Requirements Analysis, you determine what data your database will need to hold and what tasks it will need to perform to meet your users' needs.
You identify

1. business objects (things in the business environment that need to be represented in the database) and
2. business rules (restrictions on how users perceive and use data).

In the first phase of the Logical Design stage you convert the business objects and their characteristics into entities and attributes . You then create an entity-relationship (ER) diagram that graphically represents as base tables the entities, their attributes, and the relationships that exist between them.
The first course in this series covered Requirements Analysis and the Logical Design stage through the creation of the ER diagram.
The next phase in the Logical Design stage of the DBLC is to normalize the base tables you created in the ER diagram, so you can store and retrieve information in the database efficiently.