Curly Brunette Girl Shows Off In The Backyard

A back garden arises from the distribution of land around a property. Land will often surround a property, unless it is semi-detached (sharing a single wall with a neighbouring property) or terraced (sometimes called row-housing), in which two lateral walls are shared with neighbouring properties.
In these conditions, land at the back of the property is separated by the property itself, and in many cases can only be accessed by passing through the house.
That land on the side away from the normal access route to the property is called the back garden.