Town planning in its widest sense describes how we as humans try to ensure that anything we do in, on, over or under land is orderly, attractive,
works and is sustainable. Land is the key element here – and the aim is the achievement of
‘sustainability’ in what humans do. 

Town planning is described as ‘planning’, ‘urban planning’, ‘city planning’, ‘spatial planning’, ‘environmental planning’, ‘land use planning’.
Effectively any activity which affects the use or protection of land and the delivery of ‘development’. When people refer to ‘town planning, it is usually with reference to the system of ‘Town and Country Planning’, which has been in place since circa 1947 and which has a more comprehensive remit than the dictionary definition set out above. 

Different countries employ different methods and systems for the planning of their nations, the management of their resources and the way
that their nations develop. The phrase ‘Town planning’ incorporates the planning of development or protection of all types of land, be it natural, rural, or agricultural, developed or undeveloped. It also describes the planning of settlements ranging from single buildings, hamlets or villages, up to cities and urban conurbations – as well as towns.

Ever since humans evolved from being hunter gatherers to become settled farmers, with new settlements located on rivers and close to shelter and food, ‘town planning’ has been evident. Over the years town planning has evolved to become ever increasingly complex. It affects all of our lives, influencing where new development will go, where and how people live, work, play and travel. 
On the macro scale, ‘planning’ determines which areas of a country will be developed and which will be protected for nature or agriculture. Infrastructure such as power stations, reservoirs, airports, railways are planned on a national basis. 
At the micro scale, town planning determines where local homes, shops, workplaces and restaurants can be located, as well as the supporting infrastructure such as schools, parks, hospitals and libraries. In the UK, the planning system has control over every form of ‘development’ down to the siting of a fence, works to a tree, or the insertion of a window in a house.