Well, I got it from your browser.
By visiting this site, you revealed the following so-called «user agent»:

The user agent is revealed during the initial connection from your browser to the server that hosts the website.
By providing the information on what operating system you use, which browser/render engine is going to show the website and which sofware versions you have installed, a web designer or programmer can ensure that your device shows the page it was intended to be shown. Also, the detection between a desktop or mobile operating system is possible through this basic information.

From an historic point of view, some entries are left-overs of the early internet. One of the first widespread browsers used to be «Mozilla», so to ensure compatibility, almost every user agent nowadays carries its name at the beginning. However it's pretty obselete in the meantime.

Tell me more about my browser