Audio
1. PulseAudio Daemon: This is the central manager of audio devices and streams on a system. It provides a unified interface to all the different backend sound systems available, handles audio routing and provides many features like audio mixing, volume control and other goodies.
2. PulseAudio Module: A module is a piece of code that is loaded by the PulseAudio daemon. It provides additional functionality such as support for new sound systems, audio format conversion, etc.
3. PulseAudio Library: This is an easy to use library that makes it easy for applications to communicate and control the PulseAudio daemon.
4. PulseAudio Sound Server: This is the main interface between the hardware and applications. The sound server handles audio routing and provides many features like audio mixing, volume control and other goodies to the applications.
5. PulseAudio Command Line Tools: These are a set of command line tools which can be used to interact with the PulseAudio sound server. They are useful for controlling, troubleshooting, and monitoring the sound system.