Alhamd Islamic University

Provides services to the lower layers. Enables program-to-program communication and determines whether sufficient resources exist for communication. Examples are e-mail gateways (SMTP), TFTP, FTP, and SNMP (Simple Network Management Protocol).

The use of computer systems to execute a variety of office operations, such as word processing, accounting, and e-mail. Office automation almost always implies a network of computers with a variety of available programs.