It is the worker's ultimate weapon: to simply stop working, together, until demands are met. The right to do it was won through struggle, and the power behind it is one word, withdrawn labor.
A strike is a collective, organized refusal to work, used by employees to pressure an employer over wages, hours, conditions, or rights. Its power is simple: an employer cannot run without workers, so workers who stop together hold real leverage.
It rests on numbers and unity. A single worker who quits is replaced; a whole workforce that stops at once can halt production entirely. The strike turns the individual's weakness into collective strength, which is why solidarity is essential to it.
The right to strike was bitterly contested. For much of history, strikes were treated as criminal conspiracies, and strikers faced firing, blacklisting, violence, and troops. Landmark labor laws in the twentieth century finally protected the right to organize and strike for most private workers.
It remains limited and double-edged. Some workers, like many public employees, are barred from striking. And a strike is costly to the strikers too, who give up pay and risk their jobs, which is why it is the weapon of last resort, used when other means have failed.