Ardour is an open-source digital audio workstation (DAW) available for Linux, macOS, and Windows. It is a powerful and full-featured audio and MIDI workstation that is used for recording, editing, mixing, and mastering audio and MIDI tracks. Ardour is designed for professionals who need a powerful and flexible environment for creating, mixing, and mastering audio and MIDI tracks. It features a wide range of features including unlimited tracks, unlimited busses, unlimited plugins, EQ and dynamics, buses, sends, and returns, VST, AU, and LADSPA plugins, real-time effects, and more. It also has a built-in MIDI sequencer and editor, as well as support for external hardware. Ardour is a highly customizable DAW that offers an intuitive workflow and is suitable for both beginners and professionals.
Audacity is not a DAW. It is an awesome audio editor.