you are organising apps / shortcuts with the folders, the desktops allow that, but you can have the apps running on the different desktops.
when you switch desktops the running apps you can access are instantly changed.
with the folders, it is all one desktop, no seperation of tasks in the task bar.
[ office apps in one desktop,
graphics apps in a second
music player in a 3rd
all open and running, but those not on current desktop have a lower priority for cpu time.