What is a user agent?
When you visit a website, your browser provides information about your browser, operating system, device, screen resolution, and more. By interacting with a website in this way on behalf of the user, the browser acts on behalf of the user.
The purpose of UA is to allow servers and peer-to-peer networks, such as websites, to identify user information, including applications, operating systems, browsers, and browser versions, etc. This allows the website to improve the Internet experience for users in all browsers. And operating system.
For example, a website that can detect UA data can redirect mobile users to a mobile version of the website. Not all websites have UA authentication, which is one of the reasons why some websites look bad on mobile devices.