Homeland security is an American national security term for "the national effort to ensure a homeland that is safe, secure, and resilient against terrorism and other hazards where American interests, aspirations, and ways of life can thrive" to the "national effort to prevent terrorist attacks within the United States, reduce the vulnerability of the U.S. to terrorism, and minimize the damage from attacks that do occur." According to an official work published by the Congressional Research Service in 2013, the "Homeland security" term's definition has varied over time.
Homeland security is not constrained to terrorist incidents. Terrorism is violent, criminal acts committed by individuals and/or groups to further ideological goals stemming from influences, such as those of a political, religious, social, racial, or environmental nature. Within the US, an all-hazards approach exists regarding homeland security endeavors. In this sense, homeland security encompasses both natural disasters and man-made events. Thus, the domain of homeland security must accommodate a plethora of situations and scenarios, ranging from natural disasters (e.g., Hurricane Katrina, Irma) to acts of terrorism (e.g., Boston Marathon bombing, September 11 attacks).
The term came about following enactment of the Homeland Security Act of 2002 and reorganization of many U.S. government civil agencies effective March 1, 2003, to form the United States Department of Homeland Security after the September 11 attacks, and may refer to the actions of that department, the United States Senate Committee on Homeland Security and Governmental Affairs, or the United States House of Representatives Committee on Homeland Security.
The term, "Homeland Security" is not to be confused with the U.S. Department of Homeland Security (DHS). In its February 15, 2001 report, the U.S. Commission on National Security/21st Century, said the United States must change how it operates in the area of homeland security. The report recommended the creation of what was ultimately called the Department of Homeland Security.