Electromagnetism is the field of physics dealing with the study of electromagnetic fields. These types of force fields transmit the electromagnetic force between particles of matter. 
The electromagnetic spectrum is the collection of radiant energy from cosmic rays to X-rays, ultraviolet light to visible light, to microwaves as well as others. Each of these radiant energies is considered a wave or particle traveling at the speed of light. Since energy is directly proportional to frequency and inversely proportional to wavelength, mathematical formulas are used so that separate waves can be differentiated. Infrared, for example, is found within the section of the electromagnetic spectrum in which the wave numbers are roughly from 13,000 to 10 cm–1, or wavelengths from 0.78 to 1000 μm.  An increase in wave number can be considered an increase in energy as well.
Basis of Electromagnetic Force
The electromagnetic force is based on the electric charge of particles that make up matter. Every particle of matter has either a positive, negative, or neutral charge. This electric charge produces an electric field which radiates outward from the particle. When in motion an electric field generates a magnetic field whose lines of force are at right angles to its own lines of force and direction of motion. A moving magnetic field in turn produces an electric field. When an electric field vibrates this interplay between electric and magnetic fields produces a wave of alternating electric and magnetic fields that propagate at the speed of light.
Visible light makes up only a small part of the electromagnetic spectrum however man made instruments are capable of detecting a wider range of wavelengths. The lower end of the electromagnetic spectrum, those of radio and microwaves are commonly used for communication