What is Schema?
A “schema” refers to the “structure” of something.
Simply put:
A schema is a term used to describe the “structure” of data or information. For example, in a database, a schema defines how data is organized.
In more detail:
- Role of Schema: It is used to define the “structure” of databases or XML files. For instance, in a database, a schema outlines the structure of tables and the relationships between them.
- Three-Tier Schema: In databases, schemas are often divided into three layers:
- External Schema: How users view and interact with the database
- Conceptual Schema: The overall design and structure of the database
- Internal Schema: How data is physically stored
Example:
- Database Schema: Defines the tables, columns, and relationships in a database.
- XML Schema: Defines the structure and rules for an XML file.
In summary:
When you encounter the term “schema,” think of it as referring to the “structure” of something, such as a database or XML file.