A playground is an area designed for children to engage in physical activity.
Modern playgrounds often have sport equipment such as the see-saw, merry-go-round, swingset, slide, climber, walking bridge, jungle gym, chin-up bars, sandbox, parallel bars, overhead ladder, trapeze and trapeze rings, playhouses, and maze, many of which help children develop physical coordination, strength, and flexibility, as well as providing recreation and enjoyment. Common in modern playgrounds are "play structures" that incorporate many different pieces of equipment.
Sometimes the safety of playgrounds is disputed in school or among regulators. Over at least the last twenty years, the kinds of equipment to be found in playgrounds has changed, often towards safer equipment built with modern materials. For example, an older jungle gym might be constructed entirely from steel bars, while newer ones tend to have a minimal steel framework while providing a web of nylon ropes for children to climb on.
Playgrounds can be
Public, free of charge
A business with an entrance fee
Connected to a business, for customers only, e.g., at McDonald's and IKEA.
Children have devised many playground games and pastimes.
Playground is also an informal term to describe an area designed for any particular group of people. For example, "the resort spa has become a playground for millionaires".
A playground is an area designed for 
Playgrounds can be