As I zoom in with + on the Source or Program window, the horizontal bar right below the scrubber gets smaller or bigger. When it gets as small as it can get, there is a small yellow horizontal bar that appears to the right of the playhead. I read into this and still do not understand what it is doing. If anyone is willing to explain I would very much appreciate it.
That horizontal bar is showing the zoom view (the Viewing Area Bar), if I understand what you are referring to correctly. You can also click+drag on its ends to change it.
When you have zoomed in to the max, that yellow/orange bar, past the CTI/Playhead shows that you have the one Frame, and that the CTI/Playhead is at the beginning of the Frame.