Bight (knot)
The bay denotes a simple, open Tauwerksschlaufe, which is the starting point of many nodes.
In contrast, a loop is always closed and fixed ( Example: bowline ). A sling or loop or loop is also closed, but takes place under train to (example: package node).
Application
Many nodes start with a bay. The most famous is probably the Schotstek. All nodes on Slip end with a bay. The most famous Slipknoten is probably the shoe strap. The bay is part of many decorative knots and important part in the Platting.