What does it mean for the US military to carry out leapfrog operations in Vietnam?

The "leapfrog" tactics in World War II used the navy as a "jumping aid", which was mainly used for landing operations. After World War II, with the improvement of air transport capacity, "leapfrog" tactics gradually became the main theory of airborne operations of the US military. The 1983 invasion of grenada War, which shocked the world, was a typical "leapfrog" skydiving operation. American commanders abandoned the traditional tactics of landing on the beach and directly relied on airborne troops to cross Georgian defensive positions to seize the airport. Airborne soldiers parachuted at an ultra-low altitude of 150 meters, the ship did not dock, and the soldiers did not wet their boots. In just four days, they disarmed the Georgian army.