Cocotte Zone (ココット ゾーン Kokotto Zōn) is a technique used by Cocotte. She creates a barrier out of purple energy, that can be used defensively, to shield herself, or offensively to trap her opponents. It has a larger variant named Cocotte Zone Max.
It is a miniature dimension closed off from the outside world which makes it exceptionally hard to break through. This can be seen with how Goku is unable to sense those inside of the Max Cocotte Zone similar to how he couldn't sense Gotenks and Super Buu while they were inside the Hyperbolic Time Chamber or how he couldn't use Instant Transmission to get to Future Trunks and Bulma while Goku Black's Rift was active.
However, it has one weakness - at least the smaller variant - in which the user cannot attack when using this due to the user having to focus on defending himself/herself. An example of this was when Cocotte was tossed out of the ring by Android 18. It can also be broken out if one trapped in it has a certain level of ki control to blast out or if they are stronger than the user as shown by Kale and Caulifla when in their Super Saiyan Green and Super Saiyan 2 respectively.
Cocotte seems to be able to make a regular sized Cocotte Zone that has greater density than her usual ones or the Cocotte Zone Max. She used this to protect herself from Kale and Caulifla's combined beam attack which broke through the Cocotte Zone Max.