> For the complete documentation index, see [llms.txt](https://documentation.astera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://documentation.astera.com/data-model/data-models/introducing-data-models.md).

# Introducing Data Models

A data model is a logical structure that incorporates the various tables present within a database, and the relationships between them. In essence, it outlines the connections present between the datasets existing in a particular database, thus illustrating how these datasets are stored and processed within the system.

Astera Data Stack allows its users to create a data model from scratch using the entities available in the toolbox, or to generate a data model for an already existing database using the reverse engineer option. Moreover, you can also create and edit entity relationships, modify entity layouts, and add and modify indexes using this functionality.

Here is a sample data model that has been reverse engineered from an existing database.

<figure><img src="https://content.gitbook.com/content/zEifS4h8yurLAAwiGNX2/blobs/HYxx1UYqxwNzLUSRyF6S/01-introduction-to-data-models-1617790978889.PNG" alt=""><figcaption></figcaption></figure>

The boxes represent the tables present in the database and the lines connecting these boxes are an indicator of the relationships between these tables.


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