CC stands for Crowd Control

Crowd Control is Raid Term people use to describe the different Debuffs in the game.

- Provoke

- Sleep

- Stun

- Freeze

The above debuffs are generally called Crowd Control Debuffs.

These Debuffs try to control the enemy by slow them down or preventing them from doing serious damage to your team.

Example:

If you Freeze the enemy hero, The enemy will be unable to move due to the Freeze.

The enemy will have to skip their turn waking up from the Freeze.

This gives you a chance to stay alive longer.

It helps your team take less damage.

Thanks!

Also  Fear  and  True  Fear,  though  they  are  not  always  grouped  with  the  rest  due  to  having  a  50/50  chance  of  proccing