To mention, i am trying to understand the flow of electromagnetic energy from the roots and only have some basic knowledge. In case i need to refer to some material to get to the answer, kindly provide me the link for the same In which direction does the energy flow in a region (preferably vacuum) in which electric field is perpendicular to the magnetic field? The situation is not similar to a travelling electronagnetic wave, in a sense, that the electric field and magnetic field are provided externally. I have two perceptions about the situation, one is that the electric and magnetic field conditions the space and the motion of the a test particle can be used to see the nature of conditioning. The second one is that the electromagnetic energy will flow in in a direction perpendicular to the electric and magnetic field. My second perception is based on the transmission of electromagnetic energy in wires, in which the electric field as potential difference, magnetic field as current, transfer electromagnetic energy from source to bulb and the lines below which i read in a paper about transmission of electromagnetic energy: "Electromagnetic theory predicts that there will be a flow of energy through any place where electric and magnetic fields both exist and are not parallel to one another." It is obvious that one would need electrons in wires to produce magnetic field and electric field but in my question i am supplying it externally, therefore i ruled out the need of a medium and the region is assumed to be a vacuum? please tell me which perception is correct and what is wrong with my perception?