Flip-flops are a type of sandal, typically worn as a form of casual wear. They consist of a flat sole held loosely on the foot by a Y-shaped strap known as a toe thong that passes between the first and second toes and around both sides of the foot.
This style of footwear has been worn by the people of many cultures throughout the world, originating as early as the ancient Egyptians in 1,500 B.C. The modern flip-flop descends from the Japanese zōri, which became popular after World War II when soldiers returning to the United States brought them back. They became popular unisex summer footwear starting in the 1960s.