## What is a referring URL or page?
A referring page is the URL of the page that your site visitor used to arrive at a new page. This URL is called the referring URL.
## ref_url parameter
The ref_url parameter values in your API requests are populated when the Bloomreach pixel fires as your site visitor clicks a link. This parameter value identifies which page is loaded in your visitor's browser when the visitor clicks a link to move to the current page. Digital merchandisers and other business users at your organization can use this information to track visitors' activities on your site and gain a better understand of what each visitor wants to see.
When forming values for your ref_url parameters, you need to include the entire URL, not just the URI. For example, here's the ref_url parameter for a referring page that's a search request:
## How does Bloomreach use the ref_url?
Bloomreach uses the ref_url parameter value to determine how your visitors arrive at particular pages on your site. Referring pages help you and Bloomreach understand your site visitors by tracking how they arrive at your site and individual pages within your site.
A referring page is the previous page where your site visitor clicked a link that opens the current page. The ref_url parameter value is the URL of that referring page. When a visitor clicks a link to open a page, the browser sends a request to the site's server. The request includes both the destination page and the page that the visitor is leaving. Your Bloomreach pixel fires when your visitor opens the destination page, using the value of your ref_url parameter to track your site visitor.
For example, let's say that a shopper is looking at a page called Oxfords and Wingtips. Here's its URL: http://www.example.com/shoes/oxfords
The shopper clicks a link to open the product page called Wall Street Wingtips. Here is the new page's URL: http://www.example.com/shoes/wall-street-wingtips.
In this example, Oxfords and Wingtips is the referring page, and Wall Street Wingtips is the new or destination page. Here's the value for the ref_url parameter: &ref_url=http://www.example.com/shoes/oxfords
If a visitor opens your site by typing the URL directly into the browser or opening a bookmark, then the value of ref_url is empty.