Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)
Well Internet Browsers are softwares like google chrome, Firefox, Microsoft edage , Opera etc which display webservers responded html visually to users beautifully, and also provide interaction of users with web servers. Users view websites, they watch videos, do chating with friends etc but on backend its all code play and that's job of browsers to faciliate users so that users can browser internet because not everyone understand code and servers only understand code.
Well Useotools What is my Browser tool is one click too that will provide you a lot of useful information about your browser and system which include your user agent, browser version, IP address, screen resolution etc. Usage of this tool is simple you just need to be on page of what is my browser tool and it will display information on it.