Some ignorant anti-gun people seem to think the AR in AR-15 means “Assault Rifle”. Some trolls deliberately say that just to get people worked up and to waste their time.
I’d like to definitely set the issue to rest with this post. The AR in AR-15 does not mean “Assault Rifle”.
Here, for present day applications, is the definitive definition of what AR means (given appropriate legal constraints):
H/T to Phoenix @Phoenix81977532.