Position items using alignment guides
Alignment guides appear when the edges of a region you’re moving align with another region in the Tracks area, and when automation points you’re moving align with other items in the timeline. The yellow alignment guides briefly appear as the edge of the region or automation point aligns with other items in the timeline.
You can turn alignment guides on or off. Turning on alignment guides also turns on snapping, if it’s off. When the item you’re moving is close to an alignment guide, it “snaps” to the alignment guide.
Turn alignment guides on or off
Choose Edit > Alignment Guides.
When you turn alignment guides on, they appear when a region you’re moving aligns with another region in the Tracks area.