system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The levels of police officer

What's the difference between a sheriff, deputy, lieutenant, detective, etc? Why do I only see police cars with "sheriff" on them?
gpt
Sheriff is an elected position which generally derives it's powers from the Constitution of the state. Sheriffs Deputy or Sheriffs Officer are "deputized" to act on behalf of and have the powers of the Sheriff. They're also usually officers of the court and have power to enforce civil law, which is why they serve civil writs, documents related to child support, divorce, etc.

Police departments and state police are the law enforcement arm of state, county and local governments. They enforce traffic and criminal law, but cannot enforce civil matters.

Sergeant, Lieutenant, Captain, etc. are part of the rank structure, both within Sheriffs departments and police agencies. They are typically supervisors in charge of deploying resources, management and oversight.

Detective is a specialized position who focuses mainly on the investigation of crimes and apprehension of criminals. This can vary from insurance fraud to homicide to high level drug smuggling. They specialize and take courses above what a patrol officer would need for his typical day to day interactions.