Airspeed

hi guys, ok this is kinda related to fs and real life. Ok ive been trying to figure something out.
In real world civil flying do they use true air speed or indicated airspeed. The reason I ask is ive been looking at the a330 which states it has a cruise speed of around 450 + knots m.82 now the only way in flight sim you can get that is by using true airspeed not indicated.
I hope im making sence but if someone can explain between indicated and true id be grateful as i cant work out y have both?
please help
In real world civil flying do they use true air speed or indicated airspeed. The reason I ask is ive been looking at the a330 which states it has a cruise speed of around 450 + knots m.82 now the only way in flight sim you can get that is by using true airspeed not indicated.
I hope im making sence but if someone can explain between indicated and true id be grateful as i cant work out y have both?
please help