||The Center for Relativistic Laser Science (CoReLS) is a research center launched in 2012 as a GIST campus research center of the Institute for Basic Science (IBS). IBS with its headquarter in Daejeon is a research organization established to boost basic science in Korea, benchmarking the Max Planck institutes in Germany. CoReLS research focuses on the exploration of novel fundamental physical phenomena in superintense laser-matter interactions using the femtosecond PW laser facility at GIST with two PW laser beamlines of 1 PW and 1.5 PW at 30 fs. CoReLS consists of five research groups on PW laser, high-density laser plasma, low-density laser plasma, laser plasma theory, and attosecond science. The femtosecond PW Ti:Sapphire laser, currently the most powerful laser in the world and being upgraded to 4 PW, is the driving tool for laser electron acceleration, high energy proton generation, x-ray and gamma-ray production. Laboratory astrophysics and laser nuclear physics are also actively pursued to explore astrophysical plasmas and ultrafast nuclear transitions. The CoReLS research will open a new horizon in physical science by tackling unexplored extreme phenomena in time and space.