Usage
Click the all button to activate it.
Comments
As soon as the button is activated, the color yellow will appear behind the button name. When you select play, the entire animation will then be shown from the beginning to the end frame. If you had set a specific frame range with the from frame and to frame buttons, the background color of those buttons will change to grey to indicate that these buttons are not applicable with the current settings.
See also
play, from fr, to fr, loop