When a perpendicular ray of light hits a plane mirror, it is said that it reflects back the same path. But won't the incoming photons get affected or distorted by the reflected one?
Photons can even traverse a vacuum, nothing in it, so we (scientists) have a theory that says photons are a wave (like water waves) that gets transported in a field called the Electromagnetic (or EM field). The EM field is all around us and is responsible for all EM behaviour like electric fields, magnetism, photons/light. When 2 waves meet they superimpose (combine) but this is only temporary, the waves reemerge and travel on their way. The photons are like waves in the EM field.