The term safe house has several definitions. Most of them imply protection for people in danger, but why people are in danger defines how the term safe house is used. There are a few typical safe houses that can be considered:
A place where witnesses in danger may be safely protected by police prior to delivering testimony.
A shelter for battered women and their children.
A sanctuary for people who are seeking political asylum or protection from deportation.
A place to hide people in violation of the law.
From numerous films about police and organized crime, many are most familiar with the safe house as a place to hide someone who will give condemning testimony in a trial. Such a safe house is organized by the police, usually in remote location, and security measures are tight. Only a few people know the location of the house, since there is concern that discovery of location would lead to an attempt to harm the witness or the police protecting him prior to the delivery of testimony. In many films, the location of the safe house is discovered, but usually this does not occur in real life.
The second form of safe house is a shelter, which again may have a secret or protected location where mostly women and their children may hide from abusive spouses and/or parents. Battered women shelters do not typically rely on police protection, but rather on the secrecy of their location. They may have security systems and very strict rules regarding contact with outsiders in order to keep all people sheltered there protected. Only a few people who might be in contact with women who are abused know the safe house’s location. This might include medical personnel, social workers and police officers.
During the reign of slavery in the Southern US states, many people and churches in the North opened their doors to slaves escaping to Canada. These were also called safe houses, and a veritable network of them arose. There was significant danger for the people running the safe house, especially as America approached the Civil War. New laws could fine or jail people who in any way assisted fugitive slaves. It was a mark of bravery that the Underground Railroad supporters continued to provide safe houses for escaped slaves in the hopes that these people would someday be free.
Sometimes churches or individuals have taken the same approach by offering sanctuary to those seeking political asylum or attempting to evade deportation. In modern times in the US, such sanctuary from churches tends to be illegal, and may only be offered for a short period of time. Sanctuary may mostly exist so that people who seek refuge can remain in the country while they prepare better legal defenses to avoid deportation.
The safe house was also a common feature, and has become so again, for those people who are avoiding military service. Though the US currently has no draft, draft dodgers in 1970s might use a network of safe houses to avoid being sent to Vietnam, by getting into Canada. Several churches have offered temporary refuge to people already in the military who conscientiously object to participation in certain wars, like the Iraq war.