Back end is the database and server it resides on. That is where the System Administrators and Database Administrators live. They have terminal emulators and telnet to access the servers/databases. Front end is how the users access the database. "Access" is a good example. It could be a company-coded program that accesses the database, requiring a login (the login determines what data the user can access). Then, users can pull data from a GUI menu, or construct a query.