All Ribbon tabs in PowerPoint may have any number of buttons. These buttons represent commands. You’ll see that these buttons are not scattered all over the tab area. In fact, they are all neatly arranged together in Groups. Each of these Groups has a name that describes what the commands within that Group do. For example, the Slide Show tab in the Ribbon has a group named Set Up, which contains all commands that help you set up your slide show, such as changing show settings, hiding slides, rehearsing and recording slide shows, etc.
Explore working with Custom Groups within Ribbon Tabs in PowerPoint 365 for Mac.