Union Cabinet Minister - Senior minister in-charge of a ministry. A Cabinet minister may also hold additional charges of other Ministries, where no other Cabinet minister is appointed.
Minister of State (Independent Charge)- with no overseeing Union Cabinet Minister for that portfolio.
Minister of State (MoS) - junior minister with an overseeing Cabinet Minister, usually tasked with a specific responsibility in that ministry. For instance, an MoS in the Finance Ministry may only handle Taxation.