In Keynote (and also in PowerPoint), a build refers to the appearance and/or disappearance of elements (such as text, bullets, images, audio and movies) within a given slide.
Working with builds is relatively straightforward. You select the item(s) that you want to create a build for and then choose the order to activate or deactivate each element. These controls are accessible via the Build Inspector pane, which you can get to by clicking on Inspector button or with the Command-Option-i keyboard shortcut. By default, builds are activated by a click with your mouse, or via the spacebar or right-arrow key on your keyboard.
There may be times when you want to add some creativity and more Steve-ness to your builds, and automated builds provide you this functionality.
In this picture, I have three elements that I want to "build in," or have appear, on the screen. I want "Who?" to show up first, "What?" to show up second, and "I don't know" to show up third
Using the Keynote defaults, these elements would show up in the order that I click: "Who?" after the first click, "What?" after the second click, and "I don't know" after the third click.
But let's say I wanted "What?" and "I don't know" to automatically appear in sequence after I click on "Who?" To do this, I just need to change the "Start Build" options of both elements. For the "What?" build, instead of choosing "On Click," I'm going to choose the "Automatically after Build 1." And for the "I don't know" build, I'm going to choose "Automatically after Build 2." Now, "What" and "I don't know" will automatically build in after "Who?" is clicked.
One neat thing about automatic builds is that they can apply to "actions" as well. So if, in this baseball example, we want the elements to move to different bases after a build, we would apply the same "Automatically after..." logic to them.
Got more Keynote tips (or want more)? Let us know in the comments.