At Bushido we practice a wide variation of blocks, these can fall into several categories (as defined on wikipedia):
落花 (rakka, “falling petals”). The art of blocking with such force and precision as to completely destroy the opponent’s attacking motion. Examples of rakka are the most well-known blocks, such as gedan-barai (下段払い) or soto-uke (外受け).
流水 (ryūsui, “running water”). The art of flowing around the attacker’s motion, and through it, soft blocking. Examples are nagashi-uke (流し受け) and osae-uke (押さえ受け).
屈伸 (kusshin, “elasticity”). This is the art of bouncing back, storing energy while recoiling from the opponent’s attack, changing or lowering stance only to immediately unwind and counterattack. Classic examples are stance transitions zenkutsu (前屈立ち) to kōkutsu (後屈立ち) and moto-dachi (基立ち) to nekoashi-dachi (猫足立ち).
転位 (ten’i, “transposition”). Ten’i is the utilization of all eight directions of movement, most importantly stepping away from the line of attack.
反撃 (hangeki, “counterattack”). A hangeki defense is an attack which at the same time deflects the opponent’s attack before it can reach the defender. Examples of this are various kinds of tsuki-uke (突き受け), including yama-tsuki (山突き).