Pita bread is a type of flatbread.
flatbread definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
bread made in thin, circular pieces or sheets, often unleavened, as pita or matzo
flatbread definition by American Heritage Dictionary
Any of various breads made from usually unleavened dough and baked in flat, often round loaves.