Module Level (Private)

A module level variable is declared in the declarations section of a code module (standard, class or userform).
Module level variables can have two flavours either Private or Dim.
If you declare a variable at the top of a module with the Public statement it is not module level, its global level.

You must insert these statements at the very top of your modules, before any procedures or functions.
A private variable at the top of a module can only be used in the module it is declared in.
A private variable at the top of a module cannot be used outside that module.

Private or Dim ?

If you declare a module level variable with the Dim statement this is equivalent to using the Private statement.
Using Dim for module level variable can cause confusion and should be avoided.

Always use Private for Module Level variables.

Const

If you declare a module level variable with the Const keyword this is equivalent to using Private Const.
Using just Const for module level constants can cause confusion and should be avoided.

Always use Private Const for Module Level constants.

link - learn.microsoft.com/en-us/office/vba/language/reference/user-interface-help/private-statement