Policies are tasks that you are telling the computer to run. They run on some type of trigger, whether that is a recurring check-in, self service, etc. and do things like run a script, install a package, etc.
Configuration Profiles are settings that you are enforcing on the computer. Things like restrictions, passcode requirements, etc. These apply almost instantly via APNS.
Here are links that further define each of them:
Policies - https://docs.jamf.com/10.32.0/jamf-pro/administrator-guide/About_Policies.html
Profiles - https://docs.jamf.com/10.32.0/jamf-pro/administrator-guide/Computer_Configuration_Profiles.html