You can assign some predefined actions to the animation/movie and can make the animation interactive. 

1. You can assign an action to a certain frame to execute certain action 
    when the animation reaches to that frame.

2. You can assign an action to a movie clip or a button symbol to 
    execute certain action at mouse over event or mouse click event.

Few actions that are used very frequently are:
1. The Go To action jumps to a frame or scene.  
2. The Play and Stop actions play and stop movies. 
3. The Stop All Sounds action stops all sounds in the movie. 
4. The Get URL action jumps to a different URL. 
5. The If Frame Is Loaded action checks whether a frame is loaded.  
6. The On Mouse Event action assigns a mouse event or keyboard key 
     that triggers an action. 

To add an action to a frame follow the steps below:

1. Go to  Windows > Actions
    That will open an Actions Window as shown below.

2. Click on the arrow at upper right corner of the window and select
    Normal Mode.

3. Double click on the Basic Actions and it will show you the actions you
    can add to the animation, as shown in the picture below.

4. Now select the frame in the timeline, in which you want to add action.
 
5. Now double click on the action you want to add to the frame. The action will show up in the actions window as shown below.

6 You have added the action to the frame. You can learn this concept
   better when you will go to the example section of this tutorial.