Crouch jumping is a way to get through windows in Battlegrounds. In order to crouch jump, you must jump the the frame of the window and crouch while you move forward. Instead of vaulting you can use this move to go through windows. Whether you prefer crouch jumping or not it comes with some perks. Which we explained below
CROUCH JUMPING IS BETTER THAN VAULTING?
When it comes to speed of it, both options are pretty much the same. However using crouch jumping you get out of the window at a slightly faster rate but the momentum that you gain with vaulting makes both of the methods even. The benefits of crouch jumping is not about speed though. It is more about the combat readiness. Whenever you crouch jump through a window your weapon will always be available. With vaulting however you lose around half a second shooting time since your weapon will not be ready because of the animation effects.
Overall crouch jumping is better than vaulting in terms of combat readiness but when it comes to speed, both options seems to be even.