I just realized that I have lots of friends that might not be familiar with the definition of a Mormon missionary. So, I got online and found this wonderful definition.
Missionaries of The Church of Jesus of Latter-Day Saints (LDS Church) are volunteer representatives of the LDS Church who engage variously in proselytizing, church service, humanitarian aid, and community service. Mormon missionaries may serve on a full or part-time basis depending on the assignment, and are organized geographically into missions.
In October 2013 the LDS Church reported having over 80,000 full-time missionaries worldwide. Most full-time Mormon missionaries are single young men and women in their late teens and early twenties and older couples no longer with children in the home.
Missionaries are often assigned to serve far away from their homes, including other countries. Many missionaries learn a new language at a missionary training center as part of the assignment. Missions typically last two years for males and 18 months for females and 6 to 18 months for older couples. The LDS Church strongly encourages, but does not require, missionary service for young men. All Mormon missionaries serve voluntarily and do not receive a salary for their work.
Throughout the history of the LDS Church, over one million missionaries have been sent out on missions.