# What is a User Agent?

A **User Agent** is a string sent by a browser to identify itself (e.g., Mozilla/5.0 (Windows NT 10.0; Win64; x64) Chrome/123.0.0.0). **Browsify** uses this to detect and block bots or suspicious devices by analyzing their **User Agent** strings.


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# Agent Instructions: 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:

```
GET https://browsify.gitbook.io/browsify-docs/understanding-key-terms/what-is-a-user-agent.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
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.