Difraction or Diffraction: How To spell?
The word Difraction is misspelled against Diffraction, a noun meaning "The deflection and decomposition of light in passing by the edges of opaque bodies or through narrow slits, causing the appearance of parallel bands or fringes of prismatic colors, as by the action of a grating of fine lines or bars."
Diffraction has double "ff" is mispronounced as "f"Remember double 'FF' in between the strings Di & raction which should not be misspelled with single 'F'
Wrong Spelling:  Di-f-raction  Correct Spelling:  Di-ff-raction 
Find more incorrect spellings of Diffraction to spell right way.