"User agent" is a synonym for "browser". When you say "user agent" here, what you really mean is the contents of the header that identifies the user agent, i.e

"User agent" is a synonym for "browser". When you say "user agent" here, what you really mean is the contents of the header that identifies the user agent, i.e., browser. Calling it that is a little bit like referring to Chrome's developer tools as "Inspect Element" (based on the mistake that that's supposed to be its name, rather than recognizing that the label is just a simple, descriptive verb/action).