Framing
Framing in Brazilian Jiu-Jitsu is the use of your skeleton to prop an opponent up (or away) from your by channeling their force and aggression either to the ground, back at them, or more generally just away from you, or at least the ability to fully control you. This is primarily done with the blades of your forearms (the "tegatana" in Japanese martial arts), or the shins of your legs, to use as a contact surface with generally the opponent's shoulders and/or hips to prevent the opponent from advancing by redirecting their incoming force. This is particularly distinguished by contacting with the blades of bones, as opposed to contacting with the hands or feet directly, which would be posting instead.
Since framing emphasizes contact with blades of bone, it can also be used as an offensive strategy using the blades to cut through resistance and attack as opposed to just channeling resistance from the opponent defensively. In this sense, it may be referred to as "cutting" with the "tegatana" of the arms (or even the legs) as if it were a real blade for throw entries such as in pummeling exercises, which may also be done on the ground.
Framing requires a bend in the elbow and knee that make it safer and more effective than posting (on the narrow contact of the foot or hand) to support or control weight. Due to the shorter lever from a bent arm or leg, there is less torque to stress joints (where torque is directly proportional to the length of a lever). The arms and legs stay much closer to the body, which makes them harder to isolate and attack.
Framing is also closely tied to "closing the door", where the frames of your arms and legs are touching and connected to frustrate any attempt of your opponent to get in between.

