The three languages were:
1. The DDL (schema) constitutes the Data Definition Language for the database schema. The DDL's use enabled the database administrator to define the database schema, i.e., its over all blueprint.
2. The DDL (subschema) allows the definition of the specific database components that will be used by each application.
3. The DML is the Data Manipulation Language that allows us to manipulate the database contents.
Standardization is important to users and designers because it allows them to shift from one commercial application to another with little trouble when they operate at the logical level.