A theme is a set of elements for creating a presentation — placeholder text and images, coordinated colours and so on.

When you create a presentation in Keynote, you choose a theme. You can modify themes however you like after you create a new presentation and you can change which theme a presentation uses at any time.

Some placeholder text is written in lorem ipsum, Latin text that’s scrambled so it has no meaning. When you add your own text, it appears in the language you use for your computer or any language-specific input devices.