It's possible to move the contents of regions in time, without moving the regions' start or end points. This is sometimes known as "slip editing".
To do this, hold the and keys while dragging the region or regions. As you click, the cursor will change to a double-headed arrow, and when you start dragging, the time from the start of the underlying content to the start of the clicked region is displayed.
As you drag, the region start and end points will remain
fixed, but the audio or MIDI content of the region will move,
as long as the underlying source extends beyond the region bounds.