Why does that matter? Well it helps if you are in need of support. We have all heard horror stories of unhelpful tech support, who throw out cyber babble and charge up to twenty-five dollars an hour. With a support network you can ask fellow Linux users for assistance. On the flip side, there are dozens of Windows support sites, The main point is that if you are a user who is foreign to Linux, you will not be alone.
These support groups are helpful because there is a lot of different free software out there to be downloaded for Linux and sometimes things don't all work out. (perhaps due to faulty code, software conflicts, etc.)
What are these programs that you can download? Well they range from dvd software decoders to word processors. Pretty much anything you use for Windows is already installed or can be downloaded on line for free, which brings us to point #4.