from the wikipedia:
Martial law is the system of rules that takes effect when the military takes control of the normal administration of justice.
A Curfew can be one of the following:
An order by a government for certain persons to return home daily before a certain time. It can be imposed to maintain public order (such as those after the 2003 North America blackout and 2005 civil unrest in France), or suppress targeted groups (such as was enacted on Jewish people during the regime of Nazi Germany). Curfews have long been directed at certain groups in many cities or states, such as Japanese-American university students on the West Coast of the United States during World War II, African-Americans in many towns during the time of Jim Crow laws, or people younger than a certain age (usually within a few years either side of 18) in many towns of the United States since the 1980s; see below. Some jurisdictions have also introduced "daytime curfews" that would prevent high school-age youth from visiting public places during school hours or even during immediate after-school hours.
An order by the legal guardians of a teenager to return home by a specific time, usually in the evening or night. This may apply daily, or is separate per occasion (especially concerning dating), or varies with the day of the week (earlier on a so-called school night, i.e., if the minor has to go to school the next day).
A daily requirement for guests to return to their hostel before a specified time, usually in the evening or night. Arriving later has the consequence of being locked out until the morning. It allows the hostel to dispense with a doorman during the night, and improves quietness at night.
In baseball, a time after which a game must end, or play be suspended. For example, in the American League the curfew rule for many years decreed that no inning could begin after 1 A.M. local time.
Many airports operate with rules that during certain times, the airport will be effectively closed, to facilitate noise restrictions in areas under the airports flight paths. Examples include LaGuardia Airport in New York City, and Sydney Airport in Sydney, Australia. The practice is commonly known as an Operating Curfew, or Movement Restriction.