Before we consider the contrasts between cities in different parts of the world, we must examine why cities grow up.

Once this has been done we can focus on cities in the developed and developing world.Settlements initially were founded because they could produce more food than was required. Small towns could support the inhabitants with just a few farms, and so releasing people from the fields. This meant that these people could do other jobs and provide services.

As villages grew so the number of people not involved in farming grew, eventually the small villages became large towns and other factors started to play a part in the development of cities.One of the main contributing factors to the expansion of cities is transport. Transport networks were important from a very early time; from market towns needing routes to move from town to town in order to sell their goods to people commuting into and out of the cities.Transport meant that cities could trade with each other and also with foreign nations. Trade was one of the main ways of bringing wealth into the cities, especially if they are at a junction on a trade route.

Some of the world's most famous ancient cities, like Damascus in Syria, and Xian in China, lay on the Silk Road that crossed Asia, connecting China with the Mediterranean.The initial development of a city and the time at which it started to develop has a large impact on the internal structure of a city. Many old cities in Europe still retain their old core and as the city has been required to change to suit a different purpose. This means that cities such as London and Seville have large old quarters, and this affects the way in which the city is laid out.The main period during which the developed world cities developed was whilst the industrial revolution was taking place in Europe. This saw a large influx of people into the cities from the surrounding countryside, in a process known as urbanisation.

On the farms the labourers were being replaced by machinery such as tractors and threshers, this meant that people were being made redundant and so were in search of jobs in the cities. These jobs were being provided by the factory owners whom also provided basic housing for their employees. The houses were built around the factories so that they were close to their place of work.These houses were generally on the far side of the city on the opposite side to the prevailing wind, in this model from the east.

This was for two reasons, firstly because it was close to the factories and secondly the land was cheaper. The high-class housing was built on the side of the prevailing wind because it meant that all of the pollution was blown away from the houses. The middle-class housing built up around this because they could not afford the higher land prices of the high-class housing but they did not want to be around the factories. The low-class hence were not left with much choice to fill in the rest of the city. This is very close the Hoyt model of 1939, based on 142 cities in the USA.

Another model which shows us the development of a city a little better is the Burgess model of 1924. The burgess model consists of 5 concentric rings; each ring has a specific land use. However although the model is not dynamic it does allow for the development of a city. For example to begin with the city may just have had two rings; the CBD and the original settlers, this would hence be the oldest housing in the city.

As the city got larger so more and more layers were added to the model. This allowed the different cross sections of society to start to split apart.The richer inhabitants could afford to change house when theirs was becoming run down, the city became polluted or noisy, unlike the poorer people that lived there who had to put up with whatever they had or with the houses that the more affluent people had left. More and more concentric rings were added until a social gradient became apparent with the richer people living on the outside of the city and the poorer ones occupying the overcrowded inner cities.

As the graph (overleaf) shows the housing density is also higher in the inner city and the social status of the inhabitants is lower. Although this is mostly true there are some instances of gentrification, where richer people buy the run down houses, do them up and then sell them at a higher price than they bought them for.The structure of a developing world city is however, in essence, completely different. Because many of the developing world countries were at some stage colonised, they still bear out the influence of their former inhabitants. Hence countries such as India have areas that are British in architecture and layout.

Many parts of South America have Spanish and Portuguese influences, however it is not just the architecture that parallels the colonial country, it is also the structure and current thinking in terms of planning.For example Kano in Nigeria was originally an indigenous city, it was then colonised by the Dutch who had installed a railway. They built a railway station and soon there was a fair a mount of land being used for industrial purposes. The colonials did not however build inside the old city however, instead they preferred to choose the land just outside the city walls because it meant that they could spread their houses apart without being confined.The countries of the developing world were also greatly affected by the country that colonised them. For example the Spanish and the British had completely different styles of building.

Whereas the Spanish built their colonies around a central square, the British tended to build theirs with their own individual gardens and terraces. In this way the cities were each given their own character and this in turn affects the internal structure by determining who still lives where.The main difference between developing world cities and developed world cities is that in developing world cities the highest residential land value is in the centre of the city. As opposed to in a developed world city where this land is of the lowest land value, and is occupied by those in the lowest social class.

A factor of the internal structure of the city is that of segregation. In developed and developing world cities it is generally assumed that there is no segregation. This is however a misconceived idea, the inner city of a developed world city normally has many ethnic migrants because they cannot afford to move up the social gradient and out of the city. In developing world cities, the original colonists kept the indigenous people separate from their areas and so segregation grew up, now the first segregation remains because of the social indifferences.