Gamma-Ray Bursts (GRBs) are short, intense pulses of low-energy gamma-rays, lasting from fractions of a second to several hundred seconds. They originate from cosmological distances and have isotropic luminosities of $10^{51}-10^{52}$ ergs/sec, making them the most luminous objects in the sky. Most GRBs are narrowly beamed, with energies around $10^{51}$ ergs, comparable to supernovae. GRBs are followed by afterglows, which are lower-energy, long-lasting emissions in X-ray, optical, and radio wavelengths. These afterglows allow the identification of host galaxies and determination of redshifts, ranging from 0.16 to 4.5. GRBs are associated with star-forming regions and follow the star formation rate. The fireball internal-external shocks model explains GRBs, where the kinetic energy of an ultra-relativistic flow is dissipated in internal collisions, producing the GRB itself, while external shocks with circum-burst matter produce the afterglow. Observations show that GRBs have non-thermal spectra, with energy peaks at a few hundred keV and long high-energy tails. The Band function provides a good fit to the observed spectra, with a break energy around 250 keV. GRBs show variability on time scales much shorter than their duration, with pulses composed of individual pulses showing hard-to-soft evolution. GRBs are classified into long (T90 > 2 sec) and short (T90 < 2 sec) bursts. Short bursts are typically harder and have different spatial distributions compared to long bursts. X-ray Flashes (XRFs) are similar to GRBs but with lower typical energies. GRBs are associated with supernovae and stellar collapse, with evidence of Supernova bumps in afterglow light curves. GRBs are also linked to neutron star mergers and black hole accretion. Observations of GRBs and their afterglows have constrained the fireball model, which describes the emitting regions. The inner engine of GRBs is likely a black hole or a neutron star merger, with evidence of association with star-forming regions. The afterglow is modeled using relativistic blast waves and synchrotron emission, with light curves showing different phases and transitions. GRBs also emit TeV gamma-rays, neutrinos, cosmic rays, and gravitational radiation, with some detected in specific cases. The spatial distribution of GRBs shows that they are located within host galaxies, with some being dark GRBs that lack optical afterglows. Host galaxies are faint, with median apparent magnitude R ≈ 25, and are often blue and star-forming. GRBs follow the star formation rate, with evidence of their association with supernovae and stellar collapse. The distribution of GRBs is consistent with deep field galaxy counts, and theirGamma-Ray Bursts (GRBs) are short, intense pulses of low-energy gamma-rays, lasting from fractions of a second to several hundred seconds. They originate from cosmological distances and have isotropic luminosities of $10^{51}-10^{52}$ ergs/sec, making them the most luminous objects in the sky. Most GRBs are narrowly beamed, with energies around $10^{51}$ ergs, comparable to supernovae. GRBs are followed by afterglows, which are lower-energy, long-lasting emissions in X-ray, optical, and radio wavelengths. These afterglows allow the identification of host galaxies and determination of redshifts, ranging from 0.16 to 4.5. GRBs are associated with star-forming regions and follow the star formation rate. The fireball internal-external shocks model explains GRBs, where the kinetic energy of an ultra-relativistic flow is dissipated in internal collisions, producing the GRB itself, while external shocks with circum-burst matter produce the afterglow. Observations show that GRBs have non-thermal spectra, with energy peaks at a few hundred keV and long high-energy tails. The Band function provides a good fit to the observed spectra, with a break energy around 250 keV. GRBs show variability on time scales much shorter than their duration, with pulses composed of individual pulses showing hard-to-soft evolution. GRBs are classified into long (T90 > 2 sec) and short (T90 < 2 sec) bursts. Short bursts are typically harder and have different spatial distributions compared to long bursts. X-ray Flashes (XRFs) are similar to GRBs but with lower typical energies. GRBs are associated with supernovae and stellar collapse, with evidence of Supernova bumps in afterglow light curves. GRBs are also linked to neutron star mergers and black hole accretion. Observations of GRBs and their afterglows have constrained the fireball model, which describes the emitting regions. The inner engine of GRBs is likely a black hole or a neutron star merger, with evidence of association with star-forming regions. The afterglow is modeled using relativistic blast waves and synchrotron emission, with light curves showing different phases and transitions. GRBs also emit TeV gamma-rays, neutrinos, cosmic rays, and gravitational radiation, with some detected in specific cases. The spatial distribution of GRBs shows that they are located within host galaxies, with some being dark GRBs that lack optical afterglows. Host galaxies are faint, with median apparent magnitude R ≈ 25, and are often blue and star-forming. GRBs follow the star formation rate, with evidence of their association with supernovae and stellar collapse. The distribution of GRBs is consistent with deep field galaxy counts, and their