Gamma-ray bursts are one of the most energetic explosions in the universe. When a gamma-ray bursts occurs, it is often the brightest source in the entire gamma-ray sky. Due to the extreme brightness, gamma-ray bursts are detected in a wide range of distance, from our local universe to the early universe. In fact, gamma-ray bursts are one of the very few events that can be seen directly out to the era when the first star was expected to form. Gamma-ray bursts are thus powerful tools to study the environment of the early universe, and how the universe has evolved to its current stage.

Gamma-ray bursts were first discovered in the 1960s. Since then, our knowledge of these events has greatly advanced thanks to previous studies of both theoretical modelling and space and ground observations. Nowadays, gamma-ray bursts are usually classified into two groups, short and long, based on their burst durations, with the separation of about two seconds. Both the theoretical and observational evidences suggest that long gamma-ray bursts are originated from the collapse of massive stars, and thus are related to supernovae, while the short gamma-ray bursts are from the mergers of two neutron stars, or a neutron star and a black hole, and therefore also produce gravitational waves.

Although gamma-ray bursts was originally detected in the gamma-ray wavelength, now we know that the emission actually spans a wide range of spectrum. While the gamma-ray emission usually only lasts for a few seconds to a few minutes, emission in the lower energy range (X-rays, ultra-violet, optical, and radio) can last for a much longer time (from days to years). In addition, gamma-ray bursts are known sources of gravitational waves, and potential sources of neutrinos and cosmic rays. Therefore, to gether a complet set of gamma-ray burst data requires covering photos from the entire electromagnetic spectrum, nutrinos, cosmic rays, and gravitational waves (that is, the so-called "multi-messenger astronomy").