My dad is a cop. or you can call him a police officer, also known as an officer, policeperson,
What can you tell me about his job? Is it dangerous?
It can be very dangerous. He told me In most countries, "police officer" is a generic term. And it does not specify gender.
Does the term police officer mean keeping the peace?
I do believe it does. When you join the force they make all officers take a sworn oath.