The improvements in technical and economical parameters in fiber optics are considered that are leading to their increasing importance and gains in short distance optical communication systems. In cases where the distance is shorter than 1 km, the cost reduction is possible by the substitution of more expensive glass fibers with the plastic type. The advantages and disadvantages of plastic optical fibers are presented, and their characteristic data and various applications described. The possibility of using firm connectors for these fibers is also mentioned.