There are several types of powers that can disable a character temporarily in Champions Online. Most operate on a system of a "health" and a duration. As damage is dealt to the hold (by various means based on the hold type), its health is reduced, and when it reaches zero, the hold is broken. Most holds will then apply a stacking Hold Resist.
+Hold strength means more hold health applied to your holds. Sentinel gives +20% hold strength and there are some primary utility pieces that give +15% hold strength.
Crowd Control Types
The standard hold, disables the character entirely for its duration. Broken by z-mashing and damage dealt to the held target.
A short duration hold, disables the character entirely for its duration. Neither z-mashing or damage dealt have any effect on it.
A long duration hold, disabling the character entirely. Broken instantly by damage.
Roots the target in place, but they may still use abilities. Broken by z-mashing and damage dealt to the rooted target.
Reduces the target's movement speed, but they may still use abilities. Broken by z-mashing.
Causes the target to attack friend and foe indiscriminately.
Causes the target to no longer notice a target as a threat.