The Follow feature in Google Slides enables collaborators to follow each other as they work on slides. To use the follow feature you simply have to click on the avatar (name) of your collaborator(s) as they're working. You'll then be able to see what they're doing in real-time. Of course, if your collaborator isn't doing anything, you won't see anything happen on the slides.
Applications for EducationThe new follow feature in Google Slides could help to avoid situations in which one student overwrites another's changes to a Google Slides presentation. The better solution to that problem is still to have students work together either in the same physical location or via Google Meet to discuss changes to slideshows they're developing.