What is a "Palestinian Gunman"?

Western press often refer to "Palestinian gunmen" or "Palestinian fighters".  Just who are these "Palestinian gunmen"?  Are these gunmen poorly armed, as we expect, due to the Palestinian's lack of financial resources or are they well armed and well trained sharpshooters?  As you look at these Reuters pictures of "Palestinian gunmen", ask yourself one question - do these guys look like the type that would wait for somebody to shoot first?