manual/include/move-regions-with-the-mouse.html

<p>
  To move or copy a region, make sure you are in object mode. If you are
  using smart mode, the pointer must be in the lower half of the region
  to begin a move or copy operation.
</p>
<p>
  Move the pointer into the region, use a <kbd class="mouse">Left</kbd>-drag.
  The region will follow the pointer as you move it around. By default,
  the region can move freely along the timeline.
</p>
<p>
  To move a region from one track to another, simply start a move as
  described above, but move the pointer into the desired track. The
  region will follow the pointer. Note that if you have other kinds of
  tracks visible, the region will remain where it is as the pointer
  moves across them, and will then jump to the new track. This serves as
  a visual reminder that you cannot drag an audio region into an automation
  track or a bus, for example.
</p>

<h2>Move Multiple Regions</h2>
<p>
  To move multiple regions, select them before moving. Then
  <kbd class="mouse">Left</kbd>-drag one of the selected regions. All the
  regions will move, keeping their positions relative to each other.
</p>

<h2>Fixed-Time Motion</h2>
<p>
  Sometimes, you want to move a region to another track, but keeping its
  position along the timeline exactly the same. To do this, use
  <kbd class="mouse">Middle</kbd>-drag instead.
</p>