Answer
The two offices are both part of the Presidency but have distinct mandates.
The Office of the Deputy President is constitutionally established. Its central role is to assist and deputise for the President and undertake constitutional and presidentially assigned functions
The Office of the Prime Cabinet Secretary (OPCS) is established through Executive Order and principally focuses on coordination and supervision of Government Ministries and State Departments, implementation of Government policies, programmes and projects, coordination of the National Government legislative agenda and oversight of National Government operations.
The Office of the Deputy President is constitutionally established. Its central role is to assist and deputise for the President and undertake constitutional and presidentially assigned functions
The Office of the Prime Cabinet Secretary (OPCS) is established through Executive Order and principally focuses on coordination and supervision of Government Ministries and State Departments, implementation of Government policies, programmes and projects, coordination of the National Government legislative agenda and oversight of National Government operations.