Collective Bargaining: The process where working people (through their unions) negotiate contracts with their employers to determine terms of employment.
Strike: A work stoppage caused by mass refusal of employees to work. It's one way that a union can exert pressure on an employer during negotiations.
Workers' Rights: Legal rights and claimed human rights pertaining to labor relations between workers and employers. These include the right to fair wages, safe working conditions, and collective bargaining.