A section of a canal enclosed by gates at either end within which the water depth may be varied to raise or lower boats from level to level?

The section of a canal described is known as a lock. Locks are used to manage changes in water levels, allowing boats to navigate between different elevations. When a boat enters a lock, the gates close, and water is either added or removed to raise or lower the vessel accordingly. This system is essential for maintaining navigability in waterways that traverse varying terrains.