Understanding homelessness and the services involved in providing help requires a special vocabulary. Here are some of the terms most commonly used by the Department of Housing and Urban Development.

Bridge shelter
This kind of shelter provides a safe place to stay — or a bridge — for homeless individuals or families who are waiting to move into permanent housing units. These shelters provide support services and operate with low barriers to entry, with the goal of quickly placing people into permanent housing.
Continuum of Care (CoC)
This HUD-approved entity conducts homeless services planning and coordination for a defined geographic area, such as a large city, county or, in some cases, parts of a state. CoC’s responsibilities include assessing an area’s homeless needs; applying for funding; evaluating program outcomes; and operating an entry management system. According to HUD, CoCs should represent organizations such as nonprofit homeless providers, victim service providers, faith-based organizations, governments, businesses, advocates, public housing agencies, school districts, social service providers, mental health agencies, hospitals, universities, affordable housing developers, law enforcement and other organizations that serve homeless and formerly homeless veterans or people.
Emergency shelter
HUD defines an emergency shelter as any facility whose primary purpose is to provide a temporary shelter for homeless people in general, or for specific populations of homeless people, and which does not require leases or occupancy agreements.” Emergency shelters are considered to be different from temporary emergency shelters, which were a specific designation of the pandemic relief act.
Housing First
An approach to homelessness that quickly provides permanent housing for individuals and families without preconditions or barriers to entry, such as sobriety, treatment or service participation requirements. Supportive services are offered to maximize housing stability and prevent a return to homelessness. A number of studies have shown that Housing First is more effective than other homelessness responses, with a success rate of nearly 80%. The strategy developed in the 1990s by a New York psychologist as a mental health program. For more information, a full HUD briefing on the program and how it works can be found here.
Permanent housing
This designation refers to community-based housing without a designated length of stay in which formerly homeless individuals and families live as independently as possible.
Permanent supportive housing
HUD defines this as permanent housing with indefinite leasing or rental assistance paired with supportive services to help homeless people with disabilities or families who have an adult or child with a disability achieve housing stability.
Rapid Re-Housing
This type of program emphasizes housing searches and relocation services, along with short- and medium-term rental assistance, that allows homeless individuals and families (with or without a disability) to move into permanent housing as rapidly as possible.
Temporary emergency shelter
This definition was new to the Coronavirus Aid, Relief, and Economic Security Act. HUD defined this type of emergency shelter as “any structure or portion of a structure, which is used for a limited period of time because of a crisis ... to provide shelter for individuals and families displaced from their normal place of residence or sheltered or unsheltered locations.” Examples include overnight, daytime or 24-hour shelters in which program participants are provided a safe place to sleep, rest, bathe and eat, and shelters that facilitate the movement of homeless individuals and families into permanent housing, with the assistance of case managers and support services.
Transitional Housing
HUD defined this as housing that is “designed to provide homeless individuals and families with the interim stability and support to successfully move to and maintain permanent housing.” It can only be used to cover the costs of up to “24 months of housing with accompanying supportive services.” Participants in this kind of housing program must have a lease or occupancy agreement for the transitional housing.