For the sake of terminology and a little more information for why some people have problems installing addons, each directory that is inside the Community directory, IOW that directory that contains the manifest.json and layout.json files, is called a package.
Unfortunately, some developers put the “package” directory inside another directory inside their delivered zip file for some unknown reason. This then screws up a lot of people who don’t realize they need to drill down one more directory, and they instead drag that top level directory into their Community directory, and then they wonder why their newly installed addon doesn’t appear in MSFS.
One thing I do for the sake of organization is rename all the package directories I install so that the directory sorts first on type of addon (i.e. aircraft, livery, objlib, scenery, etc), and then I sort scenery based on state.