> For the complete documentation index, see [llms.txt](https://browsify.gitbook.io/browsify-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://browsify.gitbook.io/browsify-docs/understanding-key-terms/what-is-referrer.md).

# What is a Referrer?

A **Referrer** is the URL of the webpage a user came from before landing on your store (e.g., facebook.com). **Browsify** lets you block traffic from specific referrers to prevent unwanted or malicious sources.