A more thorough explanation:

Retaliation is when someone harms another person in response to an actual or perceived harm. In the context of employment, retaliation is when an employer punishes an employee for engaging in legally protected activity, such as making a complaint of harassment or participating in workplace investigations. This can include negative job actions like demotion, discipline, firing, salary reduction, or job or shift reassignment.

For example, if an employee reports sexual harassment to their employer and is then demoted or fired, that would be considered retaliation. Similarly, if an employee participates in an investigation into workplace safety violations and is then given a lower salary, that would also be retaliation.

At the federal level, the Fair Labor Standards Act makes it illegal to retaliate against an employee for filing a complaint or participating in an investigation related to the Act. This includes both written and oral complaints, as well as participation in National Labor Relations Board investigations. However, the complaint must be clear and detailed enough for a reasonable employer to understand it as an assertion of protected rights.

In international law, retaliation refers to the use of diplomatic measures or force in response to a similar use of force. For example, the tit-for-tat tariffs between China and the United States during the Trump presidency involved retaliation.

In landlord-tenant law, retaliation may refer to retaliatory eviction, which is when a landlord evicts a tenant in response to the tenant exercising their legal rights, such as reporting housing code violations.