ARA stands for Audio Random Access, an extension for plugin formats (such as VST and AU) that allows for much deeper and more efficient communication between the plugin and your DAW.

Think of a normal plugin as someone looking at audio through a "tube," seeing only what is passing through it at that exact moment.

ARA removes this tube, allowing the plugin to see the entire audio track at once. It gives the plug-in instant access to all the file's information: the notes, the pitch, the rhythm, the tempo, information about each sample, etc. Developed by Celemony (creator of Melodyne) and PreSonus, ARA eliminates the need to "transfer" the audio into the plug-in before you can edit it. Edits made in the plug-in appear immediately on the DAW track, as if the plug-in were a native part of the software. The latest version, ARA 2, has further improved this integration, synchronizing functions such as "undo". Most popular DAWs are already compatible, and the most famous examples of plugins that use ARA are Melodyne and Voice Pro.