Understanding Migration: Types and Definitions

Every year, millions of people pack up their lives and move – some travel a few districts away for a better job, others cross oceans to study or settle, and many move back and forth with the changing seasons. This constant movement of people is one of the oldest and most powerful forces shaping societies. Understanding who counts as a migrant, and the different forms migration takes, helps make sense of how cities grow, how families survive economic hardship, and how the world’s population is constantly reshuffled. This post breaks down the core definitions and the main types of migration with clear, real-world examples.

What is migration and who is a migrant?
Why definitions matter
Internal versus international migration
Internal migration
International migration
Other important types of migration
Seasonal migration
Circular migration
Step migration
Voluntary versus forced migration
How these categories overlap

What is migration and who is a migrant?

At its simplest, migration is the movement of people away from their usual place of residence to a new place, either within the same country or across an international border. A migrant, then, is anyone who makes such a move. The reasons vary enormously – people relocate for jobs, education, marriage, family reunification, or to escape conflict, persecution, and disasters.

There is no single, universally agreed definition of “migrant.” Different organisations and governments draw the line differently. The International Organization for Migration notes that while there is no universally accepted definition, the United Nations commonly treats a long-term migrant as someone who lives outside their country of origin for at least 12 months. In broad terms, migration is understood as a change in usual residence that crosses some administrative boundary – a village, a district, a state, or a nation.

Two related terms often come up. Immigration refers to people entering a place to settle, while emigration refers to people leaving a place. The same person can be both: a worker leaving Kerala for the Gulf is an emigrant from India’s perspective and an immigrant from the destination country’s perspective.

Why definitions matter

Definitions are not just academic hair-splitting. How a country defines and counts migrants affects policy, welfare schemes, and the rights people can access. The Census of India, for instance, identifies migrants in two ways: by place of birth and by place of last residence. As explained in analyses of internal migration in India, a migrant by last residence is someone living at a place different from where they previously resided for at least six months before being counted. These technical thresholds decide who shows up in official data – and who gets left out.

Internal versus international migration

The most fundamental way to categorise migration is by whether people stay within national borders or cross them. This gives us two broad types: internal and international migration.

Internal migration

Internal migration is movement within the same country – between states, districts, cities, or villages. It is by far the more common of the two. The distinction is well established: someone moving from one region to another inside their own country is an internal migrant, and this movement happens on a much larger scale than international migration worldwide.

India illustrates this vividly. According to the Migration in India (2020-21) survey, roughly 29% of Indians are migrants – close to 400 million people, most of them moving within the country. Internal migration in India is usually broken into four streams based on the direction of movement:

Rural to rural: Movement between villages, often linked to marriage and agricultural labour. This stream is dominated by women, largely because of marriage-related relocation.
Rural to urban: People leaving villages for towns and cities in search of work. This is the stream most associated with industrialisation and the growth of cities.
Urban to urban: Movement between cities, often by skilled or semi-skilled workers changing jobs.
Urban to rural: The least common stream, sometimes occurring on retirement or due to job loss in cities.

A notable pattern is the gender divide in reasons for moving. Studies of migration trends from census data show that marriage is the primary driver of migration for women, while employment is the main reason men move. Inter-state migration in India also flows in fairly predictable directions – from less developed states like Bihar, Uttar Pradesh, Rajasthan, Madhya Pradesh, and Odisha toward economically stronger states like Maharashtra, Gujarat, Delhi, Tamil Nadu, and Karnataka, as documented in studies of Indian migration patterns.

International migration

International migration occurs when people cross state boundaries to live in another country for a minimum length of time. The demographic distinction is straightforward: crossing an international border for residence makes a person an international migrant, while staying inside the country makes them an internal migrant.

International migration is much smaller in scale. In 2024, there were an estimated 281 million international migrants worldwide, representing about 3.6% of the global population. People move across borders for economic opportunity, to join family, to study, or because of political conditions back home. A student moving from one country to another to enrol in a university programme is a classic example of an international migrant.

International migrants are sometimes grouped into permanent and temporary categories. Permanent migrants intend to settle in the new country, possibly acquiring its citizenship, while temporary migrants – such as contract workers or students – typically plan to return. India has deep ties to both forms, with large numbers working temporarily in the Gulf and a substantial permanent diaspora across North America, Europe, and beyond.

Other important types of migration

The internal-international split is just the starting point. Migration also gets classified by its timing, its repetitive nature, and the degree of choice involved. Several types are especially important to understand.

Seasonal migration

Seasonal migration involves moving for part of the year, usually tied to agricultural or industrial cycles, and then returning home. It is extremely common among India’s poorer rural populations. During the dry months when farm work dries up, families travel to work sites and return when the agricultural season resumes.

The brick kiln industry is a striking example. Research on circular migrant families working in Bihar’s brick kilns describes how labour contractors often recruit male-female pairs, with young children accompanying them. Families live on-site in basic housing for the work season, typically running from October to June. Sugarcane cutting in Maharashtra follows a similar rhythm, drawing seasonal workers who are often hired by a contractor, locally called a mukadam, who pays an advance before the work begins.

Circular migration

Circular migration is the temporary and repetitive movement of a worker between a home area and a work destination, usually for employment. As described in studies of circular migration patterns, it is an established form of mobility – whether rural-to-urban or across countries – where the migrant maintains links with both home and host areas rather than choosing one permanently.

The key difference from a simple one-time move is the repeating cycle. A worker might spend several months each year at a city construction site or a distant factory, then return to their village, and repeat this for years. This pattern brings benefits like income and new skills, but also carries costs such as poor working conditions and family separation. Bihar, with the lowest per capita income among Indian states, experiences the highest circular migration in the country.

Step migration

Step migration describes movement toward a distant destination that happens in stages rather than in one leap. Instead of jumping straight from a village to a major city, a person might move from their farm to a nearby village, then to a town, and finally to a large metropolis. Each move is a “step” closer to the ultimate destination.

This pattern is common in developing regions, where moving directly to a big city may be too expensive or daunting. A rural worker might first try a small town, build up savings and confidence, and only later attempt the move to a larger urban centre. Step migration helps explain how people gradually climb the urban hierarchy over time.

Voluntary versus forced migration

Perhaps the most important distinction is the degree of choice. Migration exists on a continuum from voluntary to forced. Voluntary migration happens when people choose to move, usually for better opportunities – work, education, or joining family. Forced migration occurs when people are compelled to leave due to conflict, persecution, natural disasters, or development projects, as outlined by the International Organization for Migration’s framework on types of movement.

The clearest example of forced migration is a refugee – someone who flees their country because they fear persecution based on race, religion, nationality, social group, or political opinion. People who are displaced but remain inside their own country are called internally displaced persons, while those who have applied for refugee status but not yet received it are asylum seekers.

In reality, the line between voluntary and forced is often blurry. Someone leaving an area of extreme poverty technically “chooses” to migrate, but severe economic necessity may leave them with few real alternatives. In India, forced displacement is significant: data from the National Sample Survey indicates that around 20% of migrant households reported forced migration caused by natural disasters, social or political problems, and displacement from development projects. Such displacement increases vulnerability, sometimes pushing people into exploitative bonded labour.

How these categories overlap

It is worth remembering that these types are not neatly separate boxes. A single migrant can fall into several at once. A worker from Bihar travelling to a West Bengal brick kiln for the dry season is engaged in internal migration, seasonal migration, and circular migration all at the same time. Their move might also blur the voluntary-forced line if economic desperation drove the decision.

The categories also feed into one another. A rise in internally displaced people can contribute to a growing number of refugees and asylum seekers, which in turn raises the count of international migrants. Understanding migration means seeing these forms as connected parts of a larger, dynamic system rather than isolated phenomena.

What do you think? When the difference between a “voluntary” and a “forced” migrant is often just the amount of economic pressure a person faces, how useful is that distinction for shaping fair policies? And as seasonal and circular migration keep millions on the move within India every year, what would it take to ensure these workers have the same rights and protections wherever they go?

References

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Table of Contents

What is migration and who is a migrant? 🔗

Why definitions matter 🔗

Internal versus international migration 🔗

Internal migration 🔗

International migration 🔗

Other important types of migration 🔗

Seasonal migration 🔗

Circular migration 🔗

Step migration 🔗

Voluntary versus forced migration 🔗

How these categories overlap 🔗