Slide notes are a convenient way to prepare scripts for recording audio or video narrations for your presentation. You can add them to slides in PowerPoint, but sometimes it's more convenient to edit them right in the narration editor. The notes will also be updated in PowerPoint when you click the Save & Close button on the narration editor toolbar.
When you open the narration editor, slide notes are displayed in the left part of the screen. You can edit them right in the Notes pane. The width of the panel can be changed by moving its left border.
If you do not need the notes pane, you can close it by clicking on the X button in the top right of the pane. You can always enable the Notes pane again by selecting the Slide Notes checkbox on the View tab.
When you click Save and Close, all the changes you've made to your slide notes will be saved to the presentation.