At an airport like Atlanta, it can be very complicated in a technical sense. But in basic terms, we use radar to separate and sequence the arrivals to a point some 10-20 miles from the runway threshold. At this point we clear the crew to join and follow the Instrument Landing System, ILS or "Beam" as you called it. However, we still must manage the speeds of these aircraft until they reach the Final Approach Fix so the spacing remains adequate. At ATL and similar fields with simultaneous approaches to several parallel runways, there will be controllers assigned to monitor the aircraft closely all the way down final, and who can override communications at any time in case one aircraft strays ever so slightly from the approach course.
There are dozens of considerations to take into account during these operations, both on the ground and in the cockpit. Even though I've been vectoring for over two decades now, I'm still awed at the skill and technology involved in allowing commercial jet aircraft to land in fog so thick, I'm scared to drive over 40 mph in it.....
