This document discusses the definition and history of cities. It defines a city as having over 10,000 inhabitants with predominantly non-agricultural functions. It then summarizes the pre-industrial and industrial stages of urbanization. The pre-industrial city had fewer than 10,000 people and served military, administrative, economic and religious functions. The industrial city saw rapid growth due to factories attracting workers from rural areas. It also discusses urban morphology, structures, land use models and problems faced by cities.