Time line
Timeline is the organizer of our movie .It controls all the content of a movie .
Timeline contains three most important components of movie i.e. frames, layers, and the playhead.

To hide timeline (To increase the size of work area)
From "view menu" choose "timeline".
To view timeline
From "view menu" choose "timeline".
Frame size
We can increase or decrease the display size of frames for better view and convenience.
But it has no effect in our movie. In the above figure frame size is normal.
Click on the upper right corner of timeline (marked "A"), a frame view pop up menu appears:
Choose a size for frame view.
For your convenience I am showing here large and medium sized frames .
Medium frame view..........
.....Large frame view
Playhead indicates the current frame displayed on the Stage. In the above figure current frame is frame 1 because playhead is on frame 1. Similarly in the figure below current frame is 10th.