Not every Wifi stick works with every operating system. You should find out which stick works for which system before buying in order to avoid making a wrong purchase. The easiest way to connect a PC to the Internet is via a LAN cable, which you connect directly to the router or via PowerLine. Often this option is not available. Then you need a wifi adapter.
Most new sticks work at least with Windows 7 or Windows 10, and many devices now also work for Macs. Only with Linux systems is the matter a little more complicated. Often the drivers are not developed specifically for Linux systems, but they can still work under certain circumstances.
Many drivers were also created by users and put on the internet free of charge. However, the drivers are not official software and may contain viruses or other malware. The safest thing to do is to find out before buying whether the desired product will also work for your own system. For Linux, there are sometimes online lists of which drivers work for which systems.