Traditionally, utthita trikonasana is thought to activate the third, or manipura, chakra. This chakra is the body's energy and vitality center, and activating it through this asana is believed to dispel fear and insecurity.
Depending on the school of yoga, there might or might not be a difference between the terms utthita trikonasana and trikonasana, but where a variation is noted, the hand placement and position of the torso varies slightly. Utthita trikonasana is similar to utthita parsvakonasana (extended side angle pose), except the latter is practiced with the lead leg in virabhadrasana lunge position.
Utthita trikonasana is part of the primary series of Ashtanga yoga and a key component of other styles of yoga. A related pose is parivrtta trikonasana (revolved triangle pose), in which the upper body twists so that the opposite arm extends to the ground.