# Ways to use Lambda@Edge
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There are many uses for Lambda@Edge processing with your Amazon CloudFront distribution, such as the following examples:
+ A Lambda function can inspect cookies and rewrite URLs so that users see different versions of a site for A/B testing.
+ CloudFront can return different objects to viewers based on the device they're using by checking the `User-Agent` header, which includes information about the devices. For example, CloudFront can return different images based on the screen size of their device. Similarly, the function could consider the value of the `Referer` header and cause CloudFront to return the images to bots that have the lowest available resolution. 
+ Or you could check cookies for other criteria. For example, on a retail website that sells clothing, if you use cookies to indicate which color a user chose for a jacket, a Lambda function can change the request so that CloudFront returns the image of a jacket in the selected color.
+ A Lambda function can generate HTTP responses when CloudFront viewer request or origin request events occur.
+ A function can inspect headers or authorization tokens, and insert a header to control access to your content before CloudFront forwards the request to your origin.
+ A Lambda function can also make network calls to external resources to confirm user credentials, or fetch additional content to customize a response.

For more information, including example code, see [Lambda@Edge example functions](lambda-examples.md).

For more information about setting up Lambda@Edge in the console, see [Tutorial: Create a basic Lambda@Edge function (console)](lambda-edge-how-it-works-tutorial.md).