Council of Ministers is the official name for the body that includes all the Ministers. It usually has 60 to 80 Ministers of different ranks.
Cabinet Ministers are usually top-level leaders of the ruling party or parties who are in charge of the major ministries. Usually the Cabinet Ministers meet to take decisions in the name of the Council of Ministers. Cabinet is thus the inner ring of the Council of Ministers. It comprises about 20 ministers.
Ministers of State with independent charge are usually in-charge of smaller Ministries. They participate in the Cabinet meetings only when specially invited.
Ministers of State are attached to and required to assist Cabinet Ministers
