Black holes are formed when massive stars run out of nuclear fuel and undergo a supernova explosion. During the explosion, the star's core collapses under its own gravity, and if the core is more than three times the mass of our sun, it continues collapsing into a black hole. The gravitational force in a black hole is so strong that even light cannot escape it, hence the name black hole. This is known as the event horizon, which marks the point of no return for anything that gets too close. Black holes come in different sizes, from stellar-mass black holes, which are around 20 times the mass of the sun, to supermassive black holes, which can be billions of times more massive than the sun and are found at the centers of most galaxies. Despite being invisible, black holes can be detected by observing the effects they have on nearby stars and gas. Through studying these effects, scientists can learn more about the properties and behaviors of these mysterious cosmic phenomena. Understanding the formation of black holes is crucial in expanding our knowledge of the universe and how it evolves over time. By studying black holes, we can gain insights into the fundamental laws of physics and the processes that govern the birth and death of stars.