I always remember talking about and using earbuds, from way back before there were any canalphones, in-ears etc. Maybe back then there were a few mono in-ear things that some radios had and police/federal agents used but they were called earpieces. So, I'm in the an earbud is what the you put the foamies on camp. When Sony came with the EX71 for the masses they were canalphones for a while to differentiate between earbud and in-ears but the term stuck for a year or two then that was it. Now earbuds or earphones encompasses everything especially on web search results :)
I remember the days back on the Audio T-board with canalphone shootouts between the EX71, the Panasonic HJE50, and the Sharp MD33.