A rushing move is a move that entails either rushing somewhere to do some sort of attack, or attacking while rushing.
In the same way as projectiles, it becomes one means for attacking at far distance (depending on what, it could be unreasonable), but since one’s own body is involved, there’s a big ol’ damage hitbox, making this a weak point.
However, compared to projectiles, the attack hitbox has better priority, and the startup tends to be quick, so they often go well for combos. They are particularly good, being an aggressive means of approach and movement.
Also, a projectile can still be left quite open when evaded with a jump (for example); against this, a rushing move can often get at the opponent whereas nothing else can, which reduces the chances of counterattack.
Some rushing moves have autoblock and/or an invincible hitbox.
Examples of rushing moves include Tatsumaki Senpūkyaku and Burn Knuckle.