Understanding Contract of Service vs Contract for Service in Labour Law

Dude, textbooks explain contract of service and contract for service as if they're the same thing, but not! Jab tum log mock tests dete ho, I'm at my shift, I need some clarity. Can someone please share a real-life example or definition of this concept? Like, what's the difference between a contract of service (e.g. employee-employer) vs a contract for service (e.g. freelancer-client)? Give me something concrete to remember for CUET PG Law!