An electromagnetic wave is a possible solution of Maxwell's equations. It is a time-dependent electromagnetic field consisting of the time-dependent field component of the electric field $$\boldsymbol{E}(t)$$ and the magnetic field $$\boldsymbol{B}(t)$$, which are orthogonally aligned in vacuum. The EM wave also propagates orthogonally to $$\boldsymbol{E}(t)$$ and $$\boldsymbol{B}(t)$$ at the speed of light $$c$$.