A supernova explosion occurs to end the life of a massive star (with mass of more than 8-10 times that of the sun). These explosions create and eject the elements that make up everything around us, including the earth. The life of a massive star will be outlined, and its sudden death in a supernova event. Following the explosion, the ejected material and energy interacts with the surrounding interstellar medium to produce a supernova remnant. Supernova remnants provide mass and kinetic energy to the interstellar medium, and accelerating most of the cosmic rays we observe. The observational aspects of supernova remnant will be reviewed and related to theoretical models.