> For the complete documentation index, see [llms.txt](https://help.reasy.ai/help/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.reasy.ai/help/getting-started/engines/data-modeler.md). # Data Modeler ### What’s a Data Model? A **Data Model** visually represents how the data is organized, connected, and structured. It comprises entities, representing tables, and attributes, representing table columns. Writing queries to create tables is considered traditional. Reasy offers a visual approach to crafting your data structure. Furthermore, it provides a unique set of commands for data creation, manipulation, and deletion. ### Why do you need it? As most applications rely heavily on data, it is crucial to have the proper data model in place to efficiently manage your business processes. A data model is where you store and manage all the data that you enter manually or that is dynamically collected through the application. With a link to your UI elements, it all works behind the scenes. Your users will only see your app's interface without any clue about how their data is manipulated. In Reasy, entities come with their own set of services to create, read, update, and delete data. Furthermore, you can even join entities using [Entity Relationships](/help/getting-started/engines/data-modeler/entity-relationships.md), allowing for complex queries and analysis of the data. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://help.reasy.ai/help/getting-started/engines/data-modeler.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.