2.1. Genesis and Evolution of the Concept
Migration processes have been known since antiquity, when people were forced to leave their country due to religious persecution, ethnic conflicts, wars or natural disasters. Over time, migration has evolved. In addition to the previous causes, people left their home country in search for a better paid job or more decent living conditions 
. So, in the past, population migration was determined by non-economic causes, while current migration is mostly due to economic reasons 
The first references to the migratory phenomenon, in an incipient form, appear in the work of A. Smith “An Inquiry into the Nature and Causes of the Wealth of Nations” (1776), which shows that there was a large wage gap between rural and urban areas in Great Britain at that time, leading to the onset of a large population movement.
The term “migration” first appeared in E. Ravenstein’s “Laws of Migration” (1885), which analyzes data from the United Kingdom, but formulates a series of “laws of migration” that were later developed. According to this author, migration was mainly determined by external opportunities, and the volume of migration is inversely proportional to the distance. Furthermore, a characteristic of migration is that it is not continuous, but occurs in waves 
The notion of migrant has its origin in Latin: migrantis
, and refers to a person who moves from place to place 
. Thus, migration means, in a broad sense 
, “any form of territorial mobility of the population regardless of purpose, duration, regularity”, and in a narrow sense “a movement of people from one locality to another”.
Migration occurs for various reasons, such as: finding a better paid job or greater satisfaction, studying abroad, doing business, but also to achieve family reunification 
. Migration gives rise to a series of negative reactions 
, such as racism, xenophobia, discrimination, segregation, poverty and human trafficking, but also to a series of positive elements, such as those related to cooperation, diversity, tolerance, growth and mobility.
At the end of the 20th century–beginning of the 21st century, migration intensified as a result of a series of factors, such as globalization and the evolution of the means of transport and communication 
The 21st century is bringing a new wave of migrants to Western Europe. It has become the responsibility of the entire European Union 
to find viable solutions, because the exodus from the Mediterranean basin is not just a problem for the countries in the region. As is well known, there are different reasons for migration: wars, conflicts, poverty, discrimination, violence and persecution, family, climate change and much more. Migrants from the East, North and Central Africa have changed their route to Western Europe, many of them no longer crossing the unsafe waters of the Mediterranean 
but heading to Belarus, being attracted by opportunities to travel with a tourist visa to this country. Belarus is estimated to host between 5000 and 20,000 migrants and refugees from the Middle East and Africa. This new migration route has created tensions on the Belarusian border with other European states. However, it seems that this migration crisis in Belarus was artificially created by Minsk in response to the sanctions imposed by European states regarding the repression of a movement to challenge the political regime in that country in 2020. For now, the refugee crisis in the border between Belarus and Poland is solved because many of the immigrants agreed to go back to their countries, after the experience of living in the forests of Belarus in unfavorable weather conditions and without food, as some of them consumed all their savings in an attempt to reach the EU.
There is also a significant influx of migrants to the UK trying to enter France illegally, which has given rise to numerous tensions between the two states. This route is part of the map of illegal migration, and every day hundreds of immigrants try to cross the English Channel, in Calais, in makeshift boats, risking their lives and often losing them. According to statistics published by the British state, it seems that over 12,500 immigrants crossed the English Channel in 2021.
Therefore, international migration should be better regulated and enforced, as well as the dismantling of illegal migrant trafficking networks, as it must be guaranteed that, by virtue of the respect for the right to immigrate, the fundamental right of citizens is not violated. It should also be borne in mind that in a few decades Europe’s religious structure may change as a result of waves of immigrants from outside Europe, and that the cultural and European values will not be affected.