Ableton Live:Envelope box

Envelopes
The envelope box is used to draw in different automation types to specific clips. The audio and MIDI envelope boxes have slightly different parameters (which are specific to audio or MIDI file types), but both envelope boxes serve the same basic user functionality.

Device chooser
The first fold down menu on the left hand side is called the Device chooser. This is where you choose what the envelope automation affects. You can choose between having it affect the clip itself, the actual mixer parameters it is assigned to, or plug-in and software instrumenth parameters.

Control chooser
The control chooser is the list of envelope parameters that are available from the device in the device chooser.

Clip envelope quick chooser (Transpose,volume,pan, etc)
The buttons right below the control chooser are quick chooser buttons used to quickly select different envelope parameters.

Linked/Unlinked
This button (when on) loops the envelopes with the clip and repeats the same automation with the clip until the clip is stopped.

When unlinked, the envelope becomes becomes independent of the clips loop cycle. This will affect the loop from the start to end positions of the envelope.

Start and End
This sets the envelopes start and end points. This is only accessible when the Linked/Unlinked button is set to Unlinked.

Loop
This sets the current envelope (as defined by the Device Chooser and Control Chooser) to repeat (loop).

Position
This sets the overall position of the loop for the envelope (as defined the current Device Chooser and Control Chooser  parameters)

Length
This sets the length of the loop of the current envelope as defined by the current Device Chooser and Control Chooser .