Now, it’s not really annoying as it used to be since most DVD players are region free (or streaming). However, in the past before streaming sites were common: when one would purchase a DVD or Blu Ray from abroad, they were region locked (as the region code dictates where the disc could be read, meaning one would need a region free DVD player).

I recall purchasing a copy of shooter (Mark Wahlberg) on a normal Blu-Ray from Japan when it came out where the region code was A while I come from a country where it’s region B. Upon booting that up on a DVD player, it couldn’t read the disc (player only recognized Blu Rays that were region B but the disc was region A rendering it incompatible).