Flashbang (Flash):

A flashbang, often called a flash, is a tactical grenade that temporarily blinds and/or deafens players who are caught looking at it or are close enough to its blast. In Counter-Strike 2, it is used to break enemy sightlines, set up team pushes, retakes, and peeks, or force opponents to turn away from key angles.

Good flash usage matters because it can create a brief advantage without dealing damage, making it one of the most important utility items for coordinated play.