Simplify the following text for a Grade 18 native English-speaking person.
Original: This Category Systems scientists gives an overview of scientists in the different fields of systems science : Such as Chaos theory , Complex systems theory , Control theory , Cybernetics , Dynamical Systems , General systems theory , Living systems theory , Mathematical Systems theory , Operations researchers , Social Systems theory , Systems biology , Systems ecology , Systems engineers , and Systems theory .
Simplified: This Category Systems scientists gives an overview of scientists in the different fields op systems science : Such as Chaos theory , Complex systems theory , Control theory , Cybernetics , Dynamical Systems , Operations research , Systems biology , Systems ecology , Systems engineers , and Systems theory .