| Term | Petition | Complaint | Application |
| Meaning in Simple Words | A formal written request made to a court asking for a legal remedy or enforcement of rights | A statement made to a magistrate or police alleging that a criminal offence has been committed | A written request to the court during an ongoing proceeding or for procedural or interim relief |
| Area of Law | Mostly in constitutional rights, fundamental rights, Divorce, or writ jurisdiction, etc | Used in criminal law | Found in both civil and criminal law like holiday application, Advocate Request Application, etc |
| Who Files It (First Party) | Petitioner | Complainant | Applicant |
| Opposite Party is Called | Respondent | Accused | Respondent / Opposite Party |
| Example | Filing a writ petition in High Court to protect fundamental rights | Filing a complaint for domestic violence or cheating under IPC or BNS | Applying for bail, adjournment, or exemption from personal appearance |
