Ground support equipment which is used for airport operations and aircraft maintenance requirements. Generally ground support equipment is supporting the operations of the aircraft while parked on the ground.
The Main 3 equipment associated with
1. Air Start Unit
2. Ground Power Unit
3. Static Frequency Converter.
GSE Connected with Aircraft - See Example
GSE Connected with Aircraft - See Example

Mostly ground support equipment is not directly associated with aircraft at the time of flying. Ground equipment is always necessary to maintain aircraft service on the ground usages.
Let's take a look at 1stEquipment AIR START UNIT :
Air Start Unit :
Why air start unit? The air start unit has a high power air force ratio which is connected to high-pressure compressor piping and valves inside of air start unit extensively used to start the aircraft
engines.
Air Starter Unit - The compressed air which is forced to rotate the cylinder continuously and then fuel injected into the cylinder to start running very efficiently. Commonly these units are used for all military and commercial aircraft’s requirement.
Coming up with great another product Ground Power Unit :
Ground Power Unit :

The Ground power unit ( GPU) is providing high voltage electrical power to the aircraft engine while parked on the ground for testing the lighting and other maintenance requirements.
These units can give the external power source providing a ground power supply for the aircraft engine with high voltage electric power supply.
The Ground Power Unit is slightly differentiated from the Auxiliary Power Unit, The (APU) Auxiliary Power Unit also doing the same thing what GPU does, but the thing is Auxiliary units are separately fixed in aircraft and involves to provide the electrical power to start the aircraft main engine, But the Ground Power unit is associated with ramp (on ground) which moving anywhere to service the aircraft ground operations.
Look at the 3rd important product Static Frequency Converter :
Static Frequency Converter :
The Static Frequency Converter also comes to know as Solid state Ground Power Unit, it is part of Ground Support Equipment, These (SFC) static frequency converter units are Electro-mechanical device which converts the AC current from one frequency to another frequency. SFC can also change their voltage,
generally these SFC units are used to convert AC power from one frequency to another desired frequency like 50Hz, 60Hz, 400Hz electrical power supplies.
These type of static frequency converters are mostly used for aircraft ground support equipment power systems requirements.
About Air+Mak Industries :
Widest range of above GSE products has accurate information’s. You can find out even more products with Air+Mak Industries