Explanation
Ohm () describes the amount of resistance electricity encounters. It is one of the base units of the International System of Units (SI), and is defined as the amount of resistance that a conductor has when a force of one volt is applied across it. Ohms are used to measure the electrical resistance of a circuit, and can be used to determine the power of a circuit or the amount of current flowing through it.

Explanation
The two main applications for AC (alternate current) are power and information. AC is used to generate and transfer power to electrical devices, and is also used to carry information signals in telecommunications.

Explanation
Voltage fluctuation is a systematic variation of the voltage waveform or a series of random voltage changes of small dimensions that occur over a period of time. Voltage fluctuation can be caused by a variety of factors, such as changes in demand, changes in the power system, faults on the power system, or the switching of large loads.

Explanation
There are five common approaches to removing unwanted heat from an IT environment:
* Air conditioning: using mechanical cooling to remove heat from the air.
* Air economization: using outside air to cool the IT environment when the temperature is cooler than the desired temperature inside the data center.
* Liquid cooling: using a liquid coolant to absorb and remove heat from IT equipment.
* Evaporative cooling: using water evaporation to cool the air.
* Immersion cooling: submerging IT equipment in a liquid coolant to remove heat.