Which knot is used only in conjunction with other knots?

The half hitch is a type of knot that is designed to be used in conjunction with other knots, rather than as a standalone knot. It is typically used to secure a rope or line and can often be applied to secure a load or to help stabilize another knot. When combined with additional knots, such as the clove hitch or the figure eight knot, it enhances the overall security and effectiveness of the rigging or tying setup.

The half hitch works by creating a simple loop around an object and is most effective when it is used to tie off a line after another knot has been completed. Its primary function is to provide extra holding power and stability when tied following a primary knot, thus making it a versatile tool in various scenarios where added security is needed.