Hi @bonam durgaprasad ,
It depends majorly organization wise , however these are the common things for Admin and Developer:
Admin:
1) Responsible to add users to groups.
2) Add roles to groups or users.
3) Create Groups.
4) Manage Tickets and make them flow from one state to other.
5) You will not have master role that is admin. YOu will have ITIL role to perform admin duties.
Developer:
1) Has all rights to change the process by coding.
2) Can create workflows, can script,etc
3) He can debug issues with additional features like debugging ON.
4) Developer has technical skills but admin dont.
5) Should have javascripts, web service and other technical knowledge.
Mark my answer correct & Helpful, if Applicable.
Thanks,
Sandeep
