Hi Nikkumatti and welcome to our forum,
Approval processes are common. You'll want to define User Roles. Go to Tools->User Roles and define a role for Requester, Reviewer, and Responder. Then, you can add conditional formatting to display the view in a different color based on the user role. You can also use the user role to conditionally hide or show a section in the form. Good luck!
Patrick Halstead [InfoPath MVP]
InfoPathDev
Patrick Halstead
Project Manager at Qdabra