An ALS file is a project file created by Ableton Live, a popular digital audio workstation (DAW) used by musicians, producers, and sound designers for composing, recording, remixing, live performances, and mastering audio. Rather than containing raw audio data itself, the ALS file stores a detailed blueprint of the entire project. This includes timeline arrangements, MIDI data, plugin settings, automation curves, routing configurations, and references to external audio samples and virtual instruments used within the session. Because it acts primarily as a container for project metadata and instructions, sharing an ALS file alone is usually insufficient unless it is collected and saved along with all its dependent media files using Ableton's 'Collect All and Save' feature.