RACI Matrix - Responsible vs Accountable

ITIL: RACI Matrix

R(esponsible) – Who is responsible for actually doing it?
A(ccountable) – Who has authority to approve or disapprove it?
C(onsulted) – Who has needed input about the task?
I(Informed, kept) – Who needs to be kept informed about the task?

Reference:
The RACI Matrix – Who’s Responsible, Accountable, Consulted… and kept Informed