How many different images are there in a dynamic wallpaper? I just started using mac OS Catalina (just switched from Windows) and I love the dynamic wallpaper feature.

How many images make up the dynamic wallpaper? Does it change every 24 hours and is therefore composed of 24 different images?
The number of images can vary depending on which dynamic wallpaper is chosen.  You can see how many images there are, for yourself.  In Finder, go to the “/System/Library/Desktop Pictures/“ folder, select whichever file you are interested in, and open it in Preview.  The dynamic wallpapers all have a file extension of ‘.heic’.