vlc video key help

[biferi]

Wen I am playing a video file and I hold down the CTRL key and then keep taping the UP key or Down Key on the keyboard a Slider comes up on screen.

And I can move it up or down what is this doing ????????

And I see also if I hold the CTRL key down and tap the Left key on the keyboard the video will skip forwords but how can I get it to go Frame by Frame???