In Microsoft Access, a public Function procedure is available to all other procedures in the current database and in referencing Microsoft Access databases. However, it is not available to any other applications.
If you declare a Function procedure as private in any module by preceding it with the Private keyword, that procedure is available only to other procedures in the same module.
If a Function procedure is declared as public within a private module, such as a class module, then the procedure is available to all other procedures in that database, but is not available to other Microsoft Access databases.