(i) Pull Migration: There is a vast scope of employment in industries, trade, transport and other services in the urban centres. So, the urban centres act as magnets for the migrant population, known as ‘Pull factors’. (ii) Push Migration: Due to unemployment, hunger and starvation people are pushed out of the villages to the urban centres to find livelihood. Natural disasters like floods, droughts, earthquakes, tsunami and war also give extra “push” to migrate to other regions. Rural Settlements 1. Rural settlements are of small size which may consist of two to four houses or a few hundred houses. 2. Pollution-free environment. 3. People are primarily engaged in agriculture or other primary activities. Urban Settlements 1. Urban settlements are of bigger size in which a few thousand to a few lakh persons are living, still bigger cities are known as metro-polis. 2. Environmental pollution is a great problem with urban population. 3. People are primarily engaged in secondary and tertiary activities of which industry, trade, transport and services are important.