Term: "User Agent"
Definition
In computing, a user agent is a string that identifies the software acting on behalf of a user, such as a web browser, email client, or other application that accesses, interacts with, or retrieves content from the internet or other networks. When a web browser, for example, requests a webpage from a server, it includes a user agent string in its request header, which contains information about the browser type, version, the operating system it's running on, and sometimes the device type.
This information allows web servers and applications to tailor content to the specific capabilities or requirements of the user's device and software, ensuring compatibility and optimizing the user experience. For instance, a website might use the user agent string to determine whether to serve a mobile-optimized page or a desktop version, or to provide a version that's compatible with a particular browser's capabilities.
User agent strings can also be used for analytics purposes, helping website owners understand the breakdown of their site's visitors by browser, operating system, and device type. However, user agent strings can be spoofed or altered by users or certain software for privacy reasons or to circumvent access restrictions based on the user agent, which can limit their reliability for identifying devices accurately.