A more thorough explanation:

Complainant

A complainant is someone who starts a legal case or complaint against another person or entity. In criminal law, the complainant is the person who claims that someone else committed a crime against them. In civil law, the complainant is the person or entity who files a complaint.

• In a criminal case, the complainant is the person who was allegedly harmed by the defendant's actions. For example, if someone is accused of stealing a complainant's car, the complainant would be the car owner.
• In a civil case, the complainant is the person or entity who is seeking damages or relief from the defendant. For example, if a company is accused of breaching a contract, the complainant would be the party who entered into the contract with the company.

These examples illustrate how the complainant is the party who initiates legal action against another person or entity. They are the ones who bring the case to court or file a complaint with an administrative agency.