@feruze-- As far as I understand, public policy is about making policy that governs the public. So this is the step where the policies are thought of and put together. Public policy administration (or public administration) is where the policies are actually implemented. So this is how the policies are put into practice.
If you're asking in terms of program curriculum at schools, I suspect they're similar. If you're interested in getting a masters in public policy and administration, you will study aspects of both policy making and implementation/administration. But I think there are also schools that offer separate programs on them, so check them out.