Strike action (or simply strike) is a deliberate refusal to work on the part of multiple employees. This is a tactic often employed by labor unions during collective bargaining with an employer. If a strike takes place against the will of the leadership of the union, or without a union, it's known as a wildcat strike. In many countries, wildcat strikes do not enjoy the same legal protections as standard union strikes, and may result in penalties for the union whose members participate. A strike may consist of workers refusing to attend work or picketing outside the workplace so as to prevent or dissuade other people from working in their place or conducting business with their employer. Or, a strike may consist of workers attending or occupying the workplace, but refusing to do their jobs or leave. This is known as a sit-down strike.
Strikes may be specific to a particular workplace, employer, or unit within a workplace, or they may encompass an entire industry, or every worker within a city or country. Strikes that involve all workers are known as general strikes.
When an employer prevents employees from working, this is known as a lockout; collectively, lockouts and strikes are known as work stoppages.
Strikes first became important during the industrial revolution, when mass labour became important in factories and mines.