Migration refers to the process of spatial mobility where individuals or groups move from one geographical unit to another, involving a change in residence from the place of origin or departure to the place of destination or arrival. This transition usually involves leaving one social setting and entering another, different one. People can migrate within a country between different states or districts or between different countries. The terms used for internal and external migration are internal migration and external migration or international migration, respectively. 

When individuals move from one place to another, they move from a place of origin to a place of destination. Immigration refers to migrants who move into a new place, whereas emigration refers to migrants who move out of a place, and these terms are used only in connection with international migration. For example, migrants leaving India to settle down in the United States or Canada are immigrants to the United States or Canada and emigrants from India. 

In migration and outmigration are terms used only in connection with internal migration. In migration refers to migration into a particular area or destination, while out migration refers to movements out of a particular area or origin or place of departure of the migrant. For instance, migrants who come from Bihar or Uttar Pradesh to Punjab are considered immigrants to Punjab and out-migrants for Bihar and Uttar Pradesh.

Migration can be classified into long-range migration and short-range/seasonal migration based on time. Long-range migration is a move made for a longer period, while permanent migration is a permanent shift of population from one region to another. Seasonal migration is a temporary shift to the sites of temporary work and residence for some or several months. 

Determinants of migration include factors such as employment opportunities, education, marriage, and family reasons. Migration can impact population growth, where the place of origin experiences a decrease in population while the place of destination experiences an increase in population. 

Migration monitoring process in India 

• There are three main sources of information on migration in a country: national census, population registers, and sample surveys. 
• In India, the national census and sample surveys are the most important sources of data on internal migration. 
• The Census of India collects data on migration using two different approaches: 
• Place of birth, which identifies lifetime migrants who were born in a different location than where they currently live. 
• Place of last residence, which identifies migrants who have recently moved to a new location from their previous place of residence. 
• These approaches help to provide insights into the size and characteristics of different migrant populations in India. 

Internal Migration - Reasons and Issues 

Types of internal migration in India 

Internal migration in India can be divided into four streams based on the origin and destination of migrants: Rural to rural (R-R), Rural to urban (R-U), Urban to urban (U-U), and Urban to rural (U-R). 

1. Rural to rural (R-R): This type of migration refers to the movement of people from one rural area to another rural area. The reasons for R-R migration can vary, but may include seeking better agricultural or livelihood opportunities, natural disasters or environmental factors, or social or cultural reasons. For example, farmers from drought-affected areas may move to areas with more rainfall to find work in agriculture. 
2. Rural to urban (R-U): This type of migration refers to the movement of people from rural areas to urban areas. R-U migration is often driven by economic factors, such as seeking better employment opportunities or higher wages. Other reasons for R-U migration may include access to better healthcare, education, and social services, or to escape poverty or social marginalization in rural areas. 
3. Urban to urban (U-U): This type of migration refers to the movement of people from one urban area to another urban area. U-U migration is often motivated by job opportunities, better living conditions, or access to better social and cultural amenities. For example, people may move from smaller cities to larger ones for better job prospects or from one metropolitan area to another for access to higher education or cultural institutions. 
4. Urban to rural (U-R): This type of migration refers to the movement of people from urban areas to rural areas. U-R migration may be driven by factors such as seeking a quieter lifestyle, retirement, or returning to one's ancestral village. Other reasons for U-R migration may include access to cheaper land or housing, or to start a business or farm. 

Understanding the different streams of internal migration in India is important for policymakers and researchers to design effective policies and programs that address the challenges and opportunities associated with these movements.

Migration trends of India 

The Census of India provides detailed data on migration trends in the country. According to the latest Census conducted in 2011, the following are some key migration trends in India: 

• Internal migration: The Census data shows that internal migration is the dominant form of migration in India, with more than 450 million people having migrated within the country. Internal migration has increased significantly over the past few decades, with more people moving from rural to urban areas. 
• Rural to urban migration: Rural to urban migration has increased significantly over the past few decades. According to the 2011 Census, around 31% of the total migrants in India moved from rural areas to urban areas. 
• Inter-state migration: Inter-state migration has also increased in recent years. According to the 2011 Census, around 54% of all migrants moved to a different state within India. 
• Female migration: The Census data shows that female migration has increased in recent years. Around 45% of all migrants in India are female. 
• Educational level: The Census data also shows that there is a positive correlation between educational level and migration. More educated individuals are more likely to migrate within India for better employment and economic opportunities. 
• Migration by age: The Census data shows that younger age groups (15-29 years) are more likely to migrate compared to older age groups.

Factors responsible for Migration 

Migration is a complex and multifaceted global phenomenon that is caused by various factors. While economic factors are often cited as one of the primary drivers of migration, there are many other factors that also play a significant role. These factors can be broadly classified as "Push" and "Pull" factors. 

Push factors are those that are associated with the area of origin and can force people to leave their homes and migrate to new locations. These factors can include poor economic activity, lack of job opportunities, environmental factors such as natural disasters, climate change, and ecological degradation, social factors such as discrimination and intolerance, political factors such as persecution, conflict, and instability, health factors such as disease outbreaks and epidemics, and educational factors such as limited access to quality education. 

For instance, in areas with poor economic activity and limited job opportunities, people may feel compelled to migrate to areas with better economic prospects. Similarly, social discrimination, political persecution, and environmental degradation can create a hostile environment that forces people to migrate in search of safety and security. 

On the other hand, pull factors are those that are associated with the area of destination and attract people to migrate. These factors can include better economic opportunities, more jobs, higher wages, improved living standards, better healthcare, and education facilities, and a more conducive social and cultural environment. 

For example, people may migrate to areas with better economic prospects and higher wages, or better healthcare and education facilities, or to escape hostile social and cultural environments.