The four terms provided are closely related to civil rights activism.
Nonviolent protest is a type of nonviolent action that consists in achieving goals and fighting for a situation that needs to be improved without resorting to violence. Famous nonviolent protesters are Henry David Thoreau, Mahatma Gandhi and Martin Luther King. On the other hand, a boycott is the act of restraining oneself from using/buying something or dealing with a person or group as a way of complaining about a situation. A boycott's aim is to bring economic loss on the target. Moreover, a sit-in is a type of organized protest that consists in sitting on the floor for a long period of time to achieve a goal. A sit-in can be considered a nonviolent protest since protesters do not use violence to fight for what they think that needs to be changed. Lastly, a strike is an organized cessation of work by a body of employees that is made in order to demand for a change, such as better working conditions or better wages. Strikes became frequent during the Industrial Revolution.