"an especially meritorious contribution to the security or national interests of the United States, world peace, cultural or other significant public or private endeavors".
Here is what President Obama said about this year's recipients:
"The Presidential Medal of Freedom is not just our nation's highest civilian honor - it's a tribute to the idea that all of us, no matter where we come from, have the opportunity to change this country for the better. From scientists, philanthropists, and public servants to activists, athletes, and artists, these 21 individuals have helped push America forward, inspiring millions of people around the world along the way."
And here are the individuals who received the medal yesterday: