Photo showing a pair of blue flip flops on the sand at a seaside. These beach sandals / thongs are pictured in the sunshine, with the gentle waves of the blue sea lapping on the beachfront in the background of the picture. Flip flops are an open-toed rubber sandal with a Y-shaped thong strap than separates the big toe. This type of beach footwear is also often known as chanklas, go-aheads, jandals, slaps and step-ins, as well as pluggers and slides.