What is the difference between DAIKIN vane pump and ordinary oil pump?

There are dozens of different kinds of pumps, and endless variations. There are vane pumps, screw pumps, piston pumps and maybe some others I never heard of. You just have to study the business until you understand what kind of pump you need. Your question can not be answered in a brief paragraph.

You can go to images.google.com to search various pump types and see pictures of the major design points.