A Great Question!
In 1905, Paul Harris formed the Rotary Club of Chicago, so professionals with diverse backgrounds could exchange ideasform meaningful, lifelong friendships, and give back to their communities.
Rotary has 29,000 Clubs in 194 countries around the world. Rotary is a 'service club,' and members provide service  to their community. Service Above Self and One Profits Most Who Serves Best are Rotary’s official mottoes. Rotary offers you the opportunity to do something good for someone else. Through the Rotary Foundation and the participation of other Rotary clubs, you will have the financial and logistic support to change lives. 
Rotary is a cross-section of the world's most prominent citizens from every background. Rotarians become aware of their culture and learn to love and work with people everywhere. They become better citizens of their countries in the process.