Why do we need mapping between different schema levels?

Mapping between different schema levels is essential for ensuring data consistency and interoperability across various systems. It allows for the integration of data from diverse sources, facilitating seamless communication and understanding between different applications and platforms. Additionally, schema mapping helps in maintaining data integrity and simplifying data transformation processes, making it easier to analyze and utilize data effectively. Ultimately, it supports better decision-making by providing a cohesive view of information from disparate systems.