用户连接到我的网站时使用的设备（计算机）

I am developing a web site and am trying to make it work on all devices. I also have a page where people can report issues so I can look into them. However, I was asking for way too much info from them. I have done a lot of reading and now can determine through PHP their operating system and browser. But I still need to know what device they are using to connect. (Like Mac, Dell, HP, iPad.) I found some stuff on cell phones and tablets but is there any way of getting the info from desktop and laptop computers? As you may have guessed I'm a rookie just learning this stuff. Thanks.I am developing a web site and am trying to mak