All over the world, people are moving, for jobs or away from conflict.
In recent years, increasing numbers of people have been moving not only from one country to another, but onwards to other cities and countries where they can find better opportunities or a safe home for their family.
But how has migration evolved over the years compared to the early era of globalisation?
The International Organization for Migration (IOM) is the only international agency that deals 100 percent with migration across the board.
On this episode of Talk to Al Jazeera, we sit down with William Lacy Swing, the IOM's director general, to discuss why people move and how it affects all of us.
"I think it's helpful to look at migration in terms of human mobility. Given the advances in technology, people increasingly are going to have a foot in several camps," says Swing. "We need to think of people not necessarily staying where they come .... Why do people overstay their visas? Largely because they have a one-entry visa, if they had multiple entries, they'd go back and forth because they have two homes.
"If there were possibilities for national laws that allowed dual or multiple citizenships, why not? Portable social security systems, so that when you retire you don't have to stay where you are to collect the money, you can actually go to your original home and receive it there," he adds.
"These are all high road scenario elements that will enable this to be a much more mobile world in a much more orderly and humane fashion. We don't have that right now."
There has been a noticeable change in migration patterns. Previously a lot of migration took place from the south to north. However given the economic crisis, especially in western Europe, this trend has been reversed.
So we asked the director general if migration to the southern hemisphere is a lasting trend or whether Europe will continue to be the primary destination for migrants rather than the point of departure because of the economic crisis.
"There is a myth here that all of the migration is south to north, this is not true. There is as much south-south migration as south-north migration," explains Swing.
And why do people migrate? What are the underlying factors that lead to the increasing mobility that we have been seeing in the last decade?
"People have moved historically, I'd say more than any other reason, out of necessity and the goal is to have a world in which people move by choice," he says.
The force of migration is powerful. In total, the number of people who move across borders make up the sixth largest country in the world, and they are sending money to other countries - currently more than $440bn annually.
But in the path of this dramatic mass movement is instability and tension. People have to get used to new neighbours and new values - and it does not always work.
Violence and racism have been identified as problems caused by the migration of people.
"We have to get used to more people showing up at our doorsteps who don't look like us or speak like us," says the migration chief.
And when conflict strikes, migrants need to move, but where? And when their new home is no longer safe, who will take care of them?