What is a Hospitality Club?
Members of a Hospitality Club offer hospitality to each other - be it a bed for the night or just a tour around town.
Usually this does not involve money. Some of the clubs require a payment to sign up or contact other members though. When known, this is listed in the description.
There are some general Hospitality Clubs that are open to anyone, and many that are for special interest groups only - gays, esperantists, hitchhikers, women, you name it.
While some clubs focus on the aspect of free accommodation, traditionally most organizations have been founded and run out of the motive of bringing people together to increase intercultural understanding and build peace. So the focus there can be more on the aspect of meeting people in places you visit.