What is the fine-grained topic of the following text: For example, if you want to start Firefox, Chrome, or any other web browser, all you've got to do is hold down the CTRL-ALT-F12-SysReq-Scroll_Lock keys simultaneously while typing "browser", which will pop up a menu displaying all the browsers currently available on your system, inviting you to choose one by hitting ESC and typing the browser's name. Only return the topic.
Opening a web browser using keyboard shortcuts