Because it performs an important part in the development of plants, prepossess such as photosynthesis etc.
Light is a type of electromagnetic radiation. Human eye has the ability to sense or detect several part of the whole electromagnetic spectrum. The portion of the electromagnetic spectrum which can be sensed by the human eye having wavelength within the range between 450nm and 750nm.
Light as Energy:
Light exhibits both kinds of behaviors, wave nature as well as the particle nature. Based on the particle nature of the light, light contains particles called as the photons.
Energy of the light is given by the formula, E = hf
Light exhibits two types of nature. It exhibits wave nature and it also shows the particle nature. Based on the theory of electromagnetic radiation, every wave consists of two forms of field, i.e; magnetic field and the electric field.
Based on the particle theory of light, light is made up of particles and these particles are referred to as photons. Light contains group of particles and every particle is known as a photon and each photon has some energy related to it which depends upon the frequency of light.
According to wave theory of light it is fundamentally a wave, made up of perpendicular electric and magnetic fields. Each wave has its associated frequency, energy and wavelength.
The properties of light are that light moves in directly lines, it can be bent and it is a kind of energy. It also has the power to be reflected. Light is a natural agent which inspires sight and makes things visible.
Light is part of the electromagnetic spectrum, that ranges from radio waves to gamma rays. Electromagnetic radiation waves, as their titles suggest are fluctuations of magnetic and electric fields, which can carry energy from one area to another.
Visible light is not inherently various from the other parts of the electromagnetic spectrum with the exception that the eye can detect visible waves.
Electromagnetic radiation also can be explained in terms of a stream of photons that are massless particles each going with wavelike properties at the pace of light.