What did president kennedy mean when he said to americans, "ask not what your country can do for you, ask what u can do for your country"?

President Kennedy, in those words from his inaugural speech in 1961, wanted to urge Americans toward public service and global service.  Kennedy was instrumental in establishing the Peace Corps, which was put into place not long after his inauguration (already in March, 1961).  The Peace Corps enlisted Americans as volunteers to give their time to serving underdeveloped nations in the world.