Before I talked about RPG styles and types now lets see some samples of real battle systems
Turn based
a turn based battle system involves turns each player will takes its turn to fight and that player's turn will then end. All strategy games use this system. ( final fantasy tactics, chrono cross , fire emblem, pokemon ) at the highest state this battle system will appear in a way similar to final fantasy X known as CTB conditional turn battle.
ATB ( active time battle )
A battle system that uses a time guage, through the in game settings the time can be used to set to wait or active when the time gauge is filled the player then gets it