What is mission?
The word "mission" covers a lot of ground in terms of Christianity. In a nutshell, Christian mission is being called by God to share God's word - the gospel - with the world, often is places where there is real need, third world countries, or places where people may have never heard the gospel.
However, Christian mission does not have to be international. While it is important to reach out to those on foreign soil, all Christians have the "mission" to share the gospel in their day to day lives; with their family, friends and colleagues. We can live as "missionaries" wherever we are.