This technique allows the user to suppress their or their allies' chakra to the point that it becomes completely undetectable. This makes it impossible for sensor type shinobi to track them via chakra. As noted by Shikamaru Nara, this technique is very useful in allowing one to infiltrate an enemy's ranks. However, due to having one's chakra suppressed, they will be unable to use ninjutsu or genjutsu.
The Ōtsutsuki Clan can naturally suppress their chakra signature. A vessel which been has sufficiently changed into an Ōtsutsuki can access this ability on instinct, without being consciously aware of its existence. Unlike regular shinobi, they're still able to use ninjutsu, as Kawaki created and maintained a shadow clone while suppressing his true body's chakra. However, fellow Ōtsutsuki and vessels can detect the user regardless.