Slide: Presentation is created on slides. It lies in the centre of the PowerPoint window.
Placeholder: By default two placeholders appear in the slide when you open the PowerPoint.
Click to add notes: This space is provided to create notes if needed.
See the image:

Mini Toolbar
It is a floating toolbar that appears when you select text or right click the text. It comprises frequently used formatting tools like Bold, Italics, Font Size and Font Color.See the image:
