The number of elevator groups in a structure or module indicates how many different elevator control systems are installed in that object, with each system controlling a group of one or more elevators.

Groups of elevators are divided according to control systems, not physical proximity. Typically elevators serving different floor zones (e.g. low-rise/high-rise) within a building belong to separate groups. Elevators spaced far apart in a building are also likely to form separate groups. Service or freight elevators are usually single (constituting a separate group), but may also fall under group control.

One independently controlled elevator constitutes a group of one. Conversely, several cabs sharing one control system constitute one group, even though each cab contributes separately to the elevator total.