A Digital Audio Workstation is a software based tool for controlling the related processes of audio recording, editing, processing, mixing and mastering. The software can be hosted on generic computer equipment or in dedicated hardware.
Popular software DAWs include: Ableton, Audacity, Cubase, Logic Pro, Pro Tools, REAPER. The products can be distinguished based on features, price, OS Platform support (e.g. Windows, MAC, Linux), licencing (e.g. Open Source/Commercial), compatibility (e.g. VST support), and market prevalence (e.g. professional studio usage).
This tag should be applied when discussing techniques and problems applicable to multiple DAWs (else the specific tag should suffice).