In a DBMS, the three-schema architecture organizes data management effectively:

1. Conceptual Schema: Acts as the blueprint, defining high-level data structure and relationships without technical details. It describes what data is stored, like having Customers, Orders, and Products tables.
2. Logical Schema: Provides a detailed layout, specifying how data is organized within tables and their relationships. It defines attributes, data types, and relationships, such as OrderID and CustomerID in the Orders table and its link to the Customers table.
3. Physical Schema: Focuses on the actual implementation, detailing how data is stored on disks, including file structures and indexing methods for efficient retrieval.

Mapping ensures each schema level aligns with the others, translating the high-level design into practical implementation and ensuring efficient data storage and retrieval. Without mapping, discrepancies could lead to inefficient data management and errors.

Example: Imagine your database as a house with three floors: the conceptual, logical, and physical levels. The conceptual schema is like the blueprint of the entire house—it’s a high-level design of what rooms (data) should be where, but it doesn’t detail the materials used. The logical schema is like the detailed architectural plan—it organizes the layout with specific rooms and their functions but still doesn’t address the construction methods. The physical schema is akin to the actual construction—how the rooms are built with concrete and nails.