We'll change it back to the previous workspace by clicking on the Tilde (~) key so that we can see the Project pane, Composition window and our Timeline at the bottom. Here we can see a composition is open in the Timeline, but we can close these frames as we've closed others by simply in the Timeline, selecting the composition we want to close and using Command+W or Ctrl+W on a PC or clicking on the small x here next to the name.

If we want to switch to a different composition in the Timeline, all we need to do is click on the tab. In the Comp window you can see, there aren't multiple tabs, instead all of these compositions are located underneath this one pulldown window. Here I can click to reveal the two compositions, the first one is Tape Worm Trouble, the second one is called Hideous Twine.

If I select Hideous Twine, you will notice that in the Timeline, the tab is selected for that Composition. We will go over creating compositions a little bit later in this series and I want you to know what they look like if you happen to open up a project that already has compositions in it.

To open up a composition that may have been closed will open up the Project pane and open up the folder that contains that composition. Here I have got the four compositions and you can see by this icon that these are comps. Previously, we have seen Photoshop documents. If I open up Photoshop, you can see what those Photoshop documents look like. If I close this up and reveal the audio, we can see the Audio icon next to those.

Similarly, QuickTime has a different icon as does Illustrator or other applications source materials. Here, this icon is generated from After Effects, meaning that this source material was created here inside the Application. When we double-click on any one of these compositions, we will get both the Composition window and the Timeline open for that specific comp. You will always get a Composition and a Timeline.

Now, you might not be seeing the Timeline or the Composition, because remember, we can use the Tilde (~) key to expand the window that our cursor has hovered over. Notice the Timeline is selected here, the strong yellow line around the outside of the Timeline indicates that that window is selected. However, if I simply hover over the Comp window and use the Tilde (~) key, the Comp window will be expanded to Full Screen mode. I don't need to select the window, just hover over it with the cursor and hit the Tilde (~) key.

Again, hit the Tilde(~) key to bring it back to the previous state, I can hover over the Timeline and use the Tilde(~) key to reveal just the Timeline. Notice that when I expand its view, After Effects automatically selects it. So now, when I go back to the previous state by using the Tilde (~) key again, After Effects has automatically switched the selected window.