In social science, the term built environment, or built world, refers to the human-made surroundings that provide the setting for human activity, ranging in scale from buildings to parks. It has been defined as "the human-made space in which people live, work, and recreate on a day-to-day basis. " The "built environment encompasses places and spaces created or modified by people including buildings, parks, and transportation systems. " In recent years,[when?]public health research has expanded the definition of "built environment" to include healthy food access, community gardens, mental health, "walkability", and "bikeability".