A registry key can be thought of as a kind of file folder, but it exists only in the Windows registry. Registry keys contain registry values, just as folders contain files. Registry keys can also contain other registry keys, which are sometimes called subkeys.
What are those different HKEY registry items in Windows anyway?
The Windows registry is structured in a hierarchy, with the top registry keys called registry hives. These have special rules associated with them, but in all other respects they are registry keys.
The term "registry entry" can refer to any individual part of the Windows registry (such as a hive or value), but it is most often synonymous with a registry key.
Items in the registry are structured this way:
