Cantonment - A cantonment is essentially a permanent or semi-permanent military quarters. The infrastructure and civic administration of such cantonment areas are governed by a Cantonment Board which falls under the Union Defence Ministry.
There are 62 cantonment areas in India - Secunderabad* is the largest of these.
*As per the Cantonment Act 2006 Secunderabad is classed as a Cantonment Area. A major part of Secunderabad and some parts of the Hyderabad city itself come under the jurisdiction of the Secunderabad Cantonment Board due to a large military presence, existing right from the days of the British.
Municipality - A municipality is a local government entity which is responsible for the civic administration of a city, town, or village and its population. It is governed by a Municipal Council and its Mayor, who are all elected. It is the legal part of the Central government machinery.