Electromagnetic spectrum
The electromagnetic spectrum is made of different types of electromagnetic radiation.
White light is able to be separated in a spectrum of many various colours, where visible light is a part of continuous spectrum of electromagnetic radiation. All types of various electromagnetic waves are moving at same speed in space.( BBC News, 2015)

Figure (1) the light is refracted by ( BBC News, 2015)

Different types of radiation
There are different types of electromagnetic radiation such as: Gamma radiation, X-ray, Ultraviolet, visible light, infrared, microwave and radio wave. All types of has named are travelling at same speed into space (speed of light) and they all are transverse wave.
Frequency (Hz)
Electromagnetic radiation
Wavelength (m)
Types
highest
Gamma radiation shortest Ionising

X-ray

Ionising

Ultraviolet

Non-Ionising

visible light

Non-Ionising

infrared

Non-Ionising

microwave

Non-Ionising lowest radio wave longest Non-Ionising

Figure (2) Different types of electromagnetic radiation in electromagnetic spectrum
(National Aeronautics and Space Administration, 2015)

Figure (3) Electromagnetic radiation application

(National Aeronautics and Space Administration, 2015)
The use of wave in communication there are different types of Electromagnetic radiation that can be applied for communication such as:
Radio wave: can be used for transmit television and radio application.
Infrared: can be applied to transmit details from location to location for example: television remote control and information links between two computers
Microwave: can be used to spread signal and mobile phone.
The use of ionising and non-ionising radiation in home and workplace.
Both case of these radiation can be used in home and workplace. Non ionising radiation are not dangerous for human and body because of their low frequency, low energy and long wavelength. in other hand, ionising radiation are dangerous for human and body and causing DNA cancer, because of their high frequency, high energy and short wavelength.
Microwave oven. (Non ionising radiation)
Laser surgery eye. (Non ionising radiation)
Wireless computer networking. (Non ionising radiation) cellular phone. (Non ionising radiation) medical tracers . (ionising radiation- gamma)
Smoke detector. (ionising radiation-alpha and gamma emitter)

Figure (4) Electromagnetic spectrum
(ARPANSA - Australian Radiation Protection and Nuclear Safety Agency, 2015)

The benefit of wireless communication.
It is easy to use. easy to set up and program supporter.
It can connect anytime and anywhere.
No hassles of using cable using hot spot
Cost. the price of wireless network is low and cheap.
Flexibility. the radio wave can travel into wall and not needed to wired network.
Durability. Wireless network is solid and able to perform in long period of time.

the possible negative effect of ionising and non ionising radiation.
Alpha and beta particle: results radiation illness such as: skin burn, hair damage and loss, cancer on human body and skin lesion.