Data Independence in DBMS refers to the ability to change the schema of the database without affecting the application programs or the user views. There are two types of data independence:
Logical Data Independence: refers to the ability to change the schema of the logical level of the database without affecting the application programs or the user views. This type of data independence is achieved by using a logical data model, such as the relational model, which abstracts the data from the physical storage.
Physical Data Independence: refers to the ability to change the schema of the physical level of the database without affecting the application programs or the user views. This type of data independence is achieved by using a physical data model, such as indexing, partitioning, and buffering, which abstracts the data from the physical storage.