Fiber materials, including natural fibers discovered thousands of years ago and man- made fibers invented over a century ago, are indispensable for the basic life of humankind, as, for instance, they are woven into textiles to make us warm since ancient times. The resulting textiles also gradually become a key part of fashions, particularly in past centuries. Recently, fiber materials experience a revolutionary evolution to a new epoch with an electronic function based on the rapid advance of information technology and artificial intelligence. They may harvest energy, store energy, light, compute, communicate, and detect the environmental change both in vitro and in vivo, and many new electronic functions are further emerging for the fibers. A new direction or even a discipline, fiber electronics we previously named, has been thus generated from the above research.