Shows how strong a creature is. An exceptionally puny creature may have a Strength of 1, a deadly Tyranid Lictor has a Strength of 6 and most men have a Strength of 3. Strength tells us how hard a creature can hit in hand-to-hand combat and how easily it can hurt an opponent.
Strength
Source: Core Rulebook 3E, p. 38
How strong a creature is; determines how hard it hits and how easily it hurts an opponent in hand-to-hand combat.