The particlewave problem which we refer to was clarified somewhat in the year 1900 when Max Planck proposed that all electromagnetic energy is radiated in discrete packages which he called quanta, or singular quantum. Einstein later confirmed Plank's theory via the photoelectric effect and used the word photon to refer to these energy packages. The problem is not with nature but with our models or concepts of nature. It is always very important to remember not to let your idea or model of the way anything should be usurp the place in your mind of the way it is or might be . That place should always be open for new information whether it agrees with theory or not.
Light travels in a wave form.
More precisely, a transverse wave form. A swell or wave in the ocean is a good example of transverse wave motion. You'll notice that the rising and falling action of the wave is at right angles to the direction of travel. A simple proof of the wave theory was first demonstrated by an English physician named Thomas Young in 1802. He forced the light from a single light source to pass through a narrow slit and then forced that same light to pass through two more narrow slits placed within a fraction of an inch of each other.