High-performance computing (HPC) is typically defined as "using computing power that is vastly larger than available in a typical desktop computer". Utilizing high-performance computing requires both the hardware, i.e. supercomputer, as well as software, i.e. the tools for programming HPC applications and using the supercomputer.
Video: what is a supercomputer
High-performance computing enables breakthroughs in multiple disciplines in science and industry, ranging from understanding the origins of the universe to finding new solutions in medicine and health care, or for example fighting climate change.