What are these sliders for in Quicktime? [PHOTO]

[guru_ck]

I've never been able to figure out what the purpose of these movable sliders do in Quicktime. Can someone explain?

I highlighted them in red...

 

[MarkMS]

So you can trim parts of a video or audio. When you go to Edit>Trim to Selection ... it trims everything but the darker portion between those sliders.

 

[richard.mac]

QuickTime Player with QuickTime Pro added is like a little movie editor. you can cut, paste and trim video.

 

[dalvin200]

i like the fact that you've downloaded the movie from the internet LMAO..

 

[candyman]

They are your 'in' and 'out' points. Basically what the others said above. So you can easily crop your video clip.