Controling media "Icons" that play video and audio in finder

So I can play songs and videos on the desktop or the finder but what program plays them? quicktime or Itunes? How can I fast forward and rewind the media and how can I mazimize the screen without having to interrupt playback? Doesent make sense to me as if you would play media in windows it would be opened by a program and you had thus control. Please elaborate AppleHeadz....😁