Natural ventilation (or passive ventilation) makes use of natural forces, such as wind and thermal buoyancy, to circulate air to and from an indoor space in order to maintain good air quality. These ventilation systems work to regulate the internal air temperature as well as bring fresh air in and send state air out. This is largely achieved through the opening and closing of windows and vents which act as a source of air as well as exhaust.
Natural ventilation: single-sided ventilation, cross ventilation and stack ventilation. Source: https://www.windowmaster.com/
Natural ventilation strategies depend on the design of the building, internal thermal loads, and the positioning of openings (typically windows). Natural ventilation can be single-sided ventilation, cross ventilation or stack ventilation, depending on the building's characteristics.
Additionally, for natural ventilation it can be used also windcatchers (traditional in Persian architecture), which generally have the form of small towers installed on top of buildings and draw air from outside into a building, providing natural ventialtion in hot, arid and humid areas.
Windcatcher (for natural ventilation). Source: https://www.wikiwand.com/en/Windcatcher