One of the earliest examples of public spaces are commons. For example, no fees or paid tickets are required for entry. Non-government-owned malls are examples of 'private space' with the appearance of being 'public space'.

A public space is a social space such as a town square that is generally open and accessible. Public space has also become something of a touchstone for critical theory in relation to philosophy, (urban) geography, visual art, cultural studies, social studies and urban design. The term 'public space' is also often misconstrued to mean other things such as 'gathering place', which is an element of the larger concept of social space.

Most streets, including the pavement, are considered public space, as are town squares or parks. Government buildings which are open to the public, such as public libraries are public space. Although not considered public space, privately owned buildings or property visible from sidewalks and public thoroughfares may affect the public visual landscape, for example, by outdoor advertising.

Adam Greenfield is an American writer and designer, and is the founder and managing director of urban-systems design practice Urbanscale, based in New York. From 2008 to 2010 he was Nokia's head of design direction for user interface and services. He was born in Philadelphia, Pennsylvania in 1968.

Greenfield graduated from New York University in 1989, earning a Bachelor of Arts degree in Cultural Studies. In 1995, he enlisted in the United States Army's reserve component Special Operations Command as a Psychological Operations specialist, holding MOS 37F and eventually achieving the grade of Sergeant.

After leaving the Army, Greenfield took up work in the then-nascent field of information architecture for the World Wide Web, holding a succession of prominent positions culminating in employment at the Tokyo office of Razorfish, where he was head of the information architecture department.

He co-taught a class in the 2006 and 2007 academic years called Urban Computing at New York University's Interactive Telecommunications Program with Kevin Slavin of New York design practice area/code.