Play Button - this starts the video playing after you pause or stop the video.

Pause Button - this will pause the video, you will use this from time to time.

Stop Button - this will stop the video from playing as well it will rewind the video to the beginning and will have to start all over. 

Mute - this will mute the sound so if the phone rings you could mute the sound but to be honest pause would be better.

Volume Control - this is where you would adjust the volume up or down.

Seek Bar - this works like rewind except you have control as to where to rewind or go forward by sliding it in the direction you want.

Video Window - this will work just like the pause and play button you click on the video window and it pauses and click again and it starts again - very convenient.