In publishing, before you get to the point of seeing your book in print you need to sell the Rights to publish your book.
When a publisher offers an author a deal they will often try to secure World Rights so that they can sell the Rights to publish the book on to publishers around the world. This helps cover their costs and helps the book achieve international success - a local publisher is going to be able to publish the book more successfully for their own market.
How can I make money through licensing my rights?
Rights sales are an important aspect of a title's profitability. Markets vary around the world - books that are largely ignored in the US may be hugely popular in China and new markets are emerging all the time. Translation rights and territory rights can be sold separately to the countries that want them.
Subsidiary rights such as film options and audio editions can also be purchased by those interested. There is definitely an opportunity both to increase your readership and to make money from potential advances and ongoing royalties in foreign territories.