Cosmic Microwave Background (CMB) telescopes are specialized instruments designed to observe and study the Cosmic Microwave Background radiation. These telescopes are typically used by astronomers and cosmologists to gather data and insights into the early universe’s conditions and evolution. The CMB is a nearly uniform glow of microwave radiation that fills the universe, originating from a time when the universe was just 380,000 years old, making it a valuable source of information about the universe’s infancy.CMB telescopes are equipped with highly sensitive detectors that can measure the temperature variations in the CMB. By studying these variations, researchers can gain valuable information about the density fluctuations in the early universe, leading to a better understanding of the formation and evolution of galaxies, galaxy clusters, and large-scale cosmic structures. Prominent examples of CMB telescopes include the Planck satellite and the Atacama Cosmology Telescope (ACT). These telescopes have played a crucial role in our understanding of the universe’s history and structure.