If you develop applications that need to communicate with other computers and processes on the Internet or a local area network, you should avoid making assumptions about the user’s network settings. Ensuring fast, efficient connections to other programs and computers is an important part of providing a good user experience.
Mac OS X supports a dynamically updating networking model. Because a user may change IP addresses many times during a single session, don’t save settings based on the IP address. Use Bonjour whenever a user might otherwise be required to set an IP address. Bonjour enables automatic discovery of computers, devices, and services on IP networks. The use of Bonjour can dramatically simplify network configuration for your users. For more information on Bonjour, see Bonjour Overview
Part of Mac OS X’s Bonjour zero-configuration networking architecture is a powerful new system for publishing and discovering services on an IP network. This system finally brings simplicity and ease-of-use together with the power of TCP/IP network services.
This document gives a high level overview of how Bonjour works. It is not meant as a programming guide. Instead, this document covers the architecture of Bonjour and gives and overview of the different Application Layer Interfaces (APIs) that are available.
Adapted from Bonjour Overview.