> For the complete documentation index, see [llms.txt](https://vikram-bajaj.gitbook.io/cs-gy-6083-principles-of-database-systems/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://vikram-bajaj.gitbook.io/cs-gy-6083-principles-of-database-systems/chapter1/levels-of-abstraction.md).

# Levels of Abstraction

A DBMS has 3 levels of abstraction:

1. **Physical Level**: describes how data is stored in the database
2. **Logical/Conceptual Level**: describes the data stored in the database and the relationships between the entities
3. **View Level**: describes how users see the data; this level hides details from the application program and displays only necessary information; there can be multiple views at the view level (as shown below)

![](/files/-M5-0_2OQgQHOB1Yh6e6)