Helicopters are different. They can hover, they can land almost anywhere, they can depart and arrive without using a runway. This means the radiotelephony procedures for helicopters differ from fixed-wing aircraft in several important ways.
The most important difference is that a helicopter doesn't need a runway. It can land in a field, on a rooftop, in a designated landing area, or at any suitable location. It can also take off from non-standard areas. This changes how you communicate because ATC can't always see your position, can't always verify you're on a runway, and needs to know exactly where you're going.