Light is the energy that propagates through electromagnetic radiation, having a strict domain of wavelength and frequency.
As with any electromagnetic wave, we are dealing with the action of two vectors: intensity of electric field and induction of magnetic field. Variation of the electric field causes the magnetic field appearance that varies inversely: when the electric field is at its maximum, the magnetic one is at its minimum and vice-verse.
It is normal to be so, because there is a transfer of energy. The resultant vectors of electric field intensity and those of magnetic field induction are always perpendicular to each other. We are interested only in vector oscillation of the electric field intensity because it gives the impression of light.
As is well known, every vector is characterized by the point of application, module, direction and purpose. In the case of polarized light, the electric field intensity vector maintains its direction, the module varies, the point of application is located in its own referential origin of the vector and vector oscillation occurs in a plane space (two-dimensional space). This plan can be rotated to the left or to the right. This is related to my other article related to optical isomerism.