A database schema is a blueprint or plan that defines the structure and organization of a database. It is a visual representation of the database's logical and physical layout, including tables, columns, relationships, constraints, and other database objects.
The database schema serves as a guide for designing and building a database, as well as for accessing and managing the data within it. It provides a clear understanding of the database structure, which allows developers, administrators, and users to work together more efficiently.
The schema defines the data types, constraints, and relationships between different tables and columns in a database. It helps to ensure data consistency, accuracy, and integrity by enforcing rules and constraints on the data. Changes to the schema can be made as the requirements of the database evolve over time.