clearance is were pilots check in at there time there going to take off. For a ex: Northwest Airlines 3455 you are cleared to the Chicago Airport As filed. Climb and Maytin 8,000 ft. Dep. Freqencie is 119.65. Then the pilot repeats the information.
ground Controls the ground and tells the pilots were to taxi and what taxi-way to use.
approach is for airplanes that is approaching the airport. Approach guides them on the runway. For the ILS.or what they pick.
departure is when the plane takes off and goes to a departure freqencie and climbs to a adutittle and turns there heading
i hope that helps you. sorry about the spelling getting rushed out the door.
If this doesnt help you use what IndyTower used.