The Zora Clip allows you to clip through many acute angles and other poorly-designed obstacles. It is not incredibly useful, but it is good to know for a few specific places, since the Zora Mask is collected so early in a speedrun, and because the technique is so easy.
If done correctly, Zora Link should teleport a small bit forward, allowing you to clip through some obstacles. Two of the most useful demonstrations of the trick are shown below:
In many places, you can substitute a Zora Clip using a superslide, megaflip, or other high-speed technique. The Zora Clip is extremely easy, though, making it a good choice for both new players and for speedrunners aiming for consistency over speed.