Control Ticks apply to many aspects of the game. Your colony, outposts, conquers and relics can all have control ticks. The ticks prevent certain actions being performed, until they have exceeded a certain number. For example, if you relocate, your control ticks on your colony are reset, meaning you have to wait for them to meet or exceed 72 before being able to relocate again, and 24 ticks before your colony can be used as a teleport gate again (If you have the teleport gate construction)
Your colony has control ticks that can be reset by certain actions.
To initiate a rebellion against your conqueror, you must have 72 control ticks. When you initiate a rebellion against your conqueror, your conqueror will get an event informing him/her that you have started to rebel. Rebellion will take 24 ticks, if, during that 24 ticks, any player wins a battle on your colony, your rebellion will be quelled (Stopped without freeing you from your conqueror). If you last 24 ticks without any other players winning a battle on your colony, then you will be free of your conqueror. If at any time your rebellion is ended early (by somebody winning a battle on your colony, or by you stopping the rebellion) then your control ticks will be reset.
When you are conquered, your control ticks will be reset. You will have to wait 72 ticks to be able to initiate a rebellion. As mentioned below, your conquer cannot force-relocate you until you have re-gained 48 control ticks. You can liberate yourself at ANY time, by conquering your conqueror by military means, you will also be freed if another player conquers your conqueror.
Upon capturing a relic, it's control ticks are reset, they will also be reset if you join a new alliance.
To win and end the era before the maximum ticks, you have to control all 10 relics for at least 100 ticks on a 3 tick/hour or slower speed world. Don't let your guard down before the admin actually starts havoc, admins try to be on time but sometimes they just can't be.
When built, or captured, an outpost's control ticks are set to 0, the outpost can then only be upgraded or razed when it's control ticks reach 24, and downgraded once it reaches 6 control ticks. (upgrading/downgrading an outpost doesn't reset it's control ticks, except with Training Bases)
When upgraded, a radar becomes jammed, this can last from 3-6 ticks, but will not affect it's control ticks.
When an outpost is upgraded into a Teleport Gate, like a Radar, it's control ticks will not be reset, but it will be jammed for 3-6 ticks.
Nukes cannot be armed until the control ticks reach 24, but arming them does not reset their control ticks, meaning an outpost can be upgraded into a nuke and armed in the same tick. Arming a nuke takes 24 ticks before you can fire it.
When an outpost is upgraded into a Training Base, it's control ticks are reset, but the Training Base can be used immediately.
Infiltration ticks are like control ticks but they are not the same, go here for more on Infiltration ticks.
When you conquer a colony, the control ticks of that colnoy are reset, and you must wait until they reach 48 ticks before being able to force relocate them.