Canceling is the act of performing a second attack while the first attack is still occurring, which cancels the recovery animation of the first attack. There are several types of cancels, used for various situations.
Cancels the recovery animation of an attack by jumping. Certain attacks like Ragna's standing B cannot be jump canceled, while other attacks like his standing 6A can. There are also some attacks that can only be jump canceled if the opponent is not blocking. Jump canceling is useful for several things, like extending the length of combos, applying more pressure if the opponent is blocking or jumping away from the opponent to keep distance.
Cancels the recovery animation of an attack by dashing and closes one's distance on the opponent, useful for combos and applying pressure. Only a few moves can be dash canceled, like Ragna's standing D. Keep in mind that Dash canceling after the opponent has blocked a previous attack will leave the player wide open for an attack.
Cancels recovery animation of an attack into a Special Attack. For example, Ragna's standing 5C can be special canceled into Hell's Fang, Dead Spike, or Inferno Divider.
Mostly used for increasing the damage one can do in a combo or cutting a long recovery animation like Ragna's Inferno Divider. Also useful for when the opponent blocks an attack that has a long recovery animation. Uses 50% of the Heat Gauge.