Focus on Resource Sharing

Patterns of resource sharing vary widely in their scope and how closely users are tied together. - search engine users never need to know about one another - cooperative workers in a particular organization may share every document together

{:.def term=“Service”} A distinct part of a computer system that manages a collection of related resources and presents their functionality to users and applications.

Resources in a distributed system are managed by a program that offers a communication interface enabling the resource to be accessed and updated reliably and constantly.

{:.def term=“Server”} A running program (a process) on a networked computer that accepts requests from programs running on other computers to perform a service and responds appropriately.

The requesting processes are referred to as clients, and the overall approach is known as client-server computing.