What is the difference between agent and admin access? Will Freshcaller appear differently for both these roles?

Yes, users with an agent role have access to only specific areas of Freshcaller. This includes

the agent dashboard, customer or contact details, and call logs. 

Admins have additional access to a real-time dashboard to monitor calls, view call queues, view agent presence, and admin settings which provide options to customize Freshcaller for your business. For more details, refer to Understanding User Roles.