NS meaning in Governmental ?

National service is a system of either compulsory or voluntary government service, usually military service. Conscription is mandatory national service. The term national service comes from the United Kingdom's National Service (Armed Forces) Act 1939.

Many young people spend one or more years in such programmes. Compulsory military service typically requires all citizens to enroll for one or two years, usually at age 18 (later for university-level students). Most conscripting countries conscripts only men, but Norway, Sweden, North Korea, Israel, Morocco, and Eritrea conscript both men and women.

Voluntary national service requires only three months of basic military training. The US equivalent is Selective Service. In the United States, voluntary enrollments at the Peace Corps and AmeriCorps are also known as national service.