A pose that involves linking the hands (or sometimes a hand to a wrist) in a process that rotates both the shoulders and the torso is called a bind. This link causes the body to be "bound" and held as a container, and therefore constricted in some ways by the arms and hands. Binds require flexibility both in the physical body -- in order to come into and maintain the pose -- and in the mind, in order to stay present and sustain the pose.
If you’re looking to go physically deeper into a pose and increase the effects of rotation, binds can be an excellent way to do this. They also offer a different way to explore and experience alignment by forcing you to make adjustments to make the pose work. Binds allow you to be curious, to play, and to be your own teacher -- in other words, they’re fun!