Most competitive smallbore rifle shooters in the United States live in a schizophrenic world, split between National Rifle Association (NRA) and International Shooting Sports Federation (ISSF) styles of competition. There may be a few who only shoot one type or the other, but most end up competing in both. It is a shooting world divided by a difference in targets, equipment, and courses-of-fire: A dichotomy unique to this country.
A short history lesson is needed to understand why shooting in the United States developed as it has and not in lockstep with Europe. Although it is certain that contests of hitting an object at a distance with a rock, spear, or sling date back to prehistoric times (the story of David and Goliath, for example), competitive target shooting, as we know it, has its roots in medieval Europe.
Why is it called Conventional?
by Hap Rocketto
https://www.ssusa.org/articles/2017/2/21/why-is-it-called-conventional/
Competition Shooting History: The Longbow
https://firearmusernetwork.com/competition-shooting-history-the-longbow/