When you are pressing or pulling, you generally want the wrist in a straight alignment. That's lining up the plane of the back of your hand with the plane of your forearm, with the wrist neither bent back nor goose-necked forward.
A bent back wrist forces the wrist to support the full load of whatever you are pressing (you'll rarely see this in pulling).
A goose necked wrist (seeing more in pulling) changes the load from a back-and-arm muscle combination to "how much can I wrist curl?" I see this a lot on single-arm cable rows, where the trainee wants to pull the handle back as far as it will go. Ironically this actually shortens the range of motion a bit and again makes the wrist the weak point.
A straight wrist, conversely, is both firm and strong. It can support a heavier load, and without the need to flex or bend under a load you don't risk as much strain.
So when you press or pull, think of keeping your wrist straight and see what a difference that can make.
How did this come up? Well, the best way to catch a heavy kettlebell clean is with a straight wrist. I left mine slightly bent on a heavy rep and caught the bell hard and flush against my wrist. It will bruise nicely. Had I punched my hand through the handle and caught it against a straight wrist, neither goose-necked or bent back (like mine was) it would have softly landed.