The Department of Homeland Security is headed by the Secretary of Homeland Security with the assistance of the Deputy Secretary. The Department contains the components listed below.
United States Citizenship and Immigration Services:
Processes and examines citizenship, residency, and asylum requests from aliens.
U.S. Customs and Border Protection: Law enforcement agency that enforces U.S. laws along its international borders (air, land, and sea) including its enforcement of U.S. immigration, customs, and agriculture laws while at and patrolling between all U.S. ports-of-entry.
U.S. Immigration and Customs Enforcement
: Law enforcement agency divided into two bureaus:
An agency that enforces U.S. laws while it investigates and gathers intelligence on national and international criminal activities that threaten the security of the homeland (Homeland Security Investigations); and
An agency that investigates violations of the Immigration and Nationality Act and enforces the detention, deportation and removal of violators of United States immigration law (Enforcement and Removal Operations).
Transportation Security Administration: Responsible for aviation security (domestic and international, most notably conducting passenger screenings at airports), as well as land and water transportation security
United States Coast Guard: Military service responsible for law enforcement, maritime security, national defense, maritime mobility, and protection of natural resources.
United States Secret Service: Law enforcement agency that investigates threats against and provides protective services for the President and Vice President of the United States and their immediate families as well as other important governmental officials. It also investigates crimes against the U.S. monetary system including the crime of counterfeiting U.S. currency and other financial instruments.
Federal Emergency Management Agency: agency that oversees the federal government's response to natural disasters like earthquakes, hurricanes, tornadoes, floods, forest fires, etc.