The flood of migrants and refugees into Europe this year — more than a half-million so far, many fleeing the civil war in Syria and other conflict zones — has sorely strained the Continent’s ability to absorb them. Leaders argued bitterly for weeks before the European Union could adopt a plan on Tuesday to share the burden among its members.

The plan will require some countries to accept refugees and some people to be relocated whether they like it or not, raising issues of freedom, rights and obligations under international law. Here are answers to some of the key questions.

Q. Can refugees choose where they get asylum?

A. To a certain extent, yes. People fleeing war or persecution are free to choose where to seek asylum. Most often it will be a neighboring country or the first safe place they are able to reach, but it could also be a country halfway around the world. Under international law, nations have a legal duty not to turn refugees away; they must be allowed to apply for asylum, even if they have entered a host country’s territory illegally.

But it is up to each host country to decide under its own laws whether to allow refugees to stay there permanently and whether they and their children can become citizens, among other issues.