What is the examples of three levels of schema?

Schemas can be classified into three levels: physical schema, logical schema, and view schema. The physical schema refers to the actual storage of data on hardware, detailing how data is stored in files and disks. The logical schema defines the structure of the database in terms of tables and relationships, abstracting away the physical details. Lastly, the view schema presents how data is seen and interacted with by users, often representing a subset or specific aspect of the logical schema tailored for particular applications or user roles.