Final Fantasy IV was the first SNES installment in Square Enix's JRPG series, originally released as "Final Fantasy II" in North America during 1991.
This is the first Final Fantasy game that introduced the famous ATB (active-time battle) system which brings a real-time element to turn-based battles: during the battles, you have a time indicator for each party member that dictates when this character is able to act. Depending on gameplay settings, enemies are also free to act in real-time regardless of whether or not a party member is capable of accepting commands from the player.
The game abandons the job system that was implemented in the first and the third Final Fantasy titles in favor of pre-set character classes (paladin, white mage, ninja, etc.) assigned to each party member.
Final Fantasy IV would see several remakes in the years following its SNES release on future game platforms including the Sony PlayStation, Nintendo DS and Apple iOS.