Flower power is a phrase describing the subculture, youth movement that began in US in early 60’s and was fast spread around the world.
Originally hippie was used to describe people beatniks, who created their own communities, listened to rock music, embraced sexual revolution and used soft drugs as grass or more hard like LSD all to discover alternative states of living, feeling. This movement grows with the war in background and naturally became opposite to it.
Peace, love music and happiness that words describe it the most. Even now hippie a still big movement have their imitative in many cultures and subcultures, hippie had a major effect on music, television, film, literature, fashion. I our world their legacy maybe observe in forms like healthy food, music festivals, I think also in cybernetic revolution.