City and regional planning is constantly challenged by the transformation of society as well as by changes in our knowledge about and understanding of the world. In broadest sense, city and regional planning is the process by which communities attempt to control and design the positive changes should take place in developing their physical environments. It has been practiced under many names including town planning, city planning, community planning, land use planning, and physical environment planning, and the like. The object of planning is not only the physical environment, which is taken to mean land use and transportation, and their interactions that have tangible existence on the land surface, but also socio-cultural and economic environments that are intangible in nature but reflect on the physical environment.
The vital concern of planning is the relations between natural and built (physical) environments, and interactions between people and their surrounding and global environments. Human activities always have negative consequences upon the natural environment, just as certain natural conditions are hazardous to human well-being. City and regional planners are equally concerned to protect natural environments from the adverse effects of human use (e.g., air, water pollution), and to protect people from environments (e.g., flood plains) where risk is involved.