Eschatology is the part of theology that is concerned with what are believed to be the last events in history. It also looks at the destiny of humanity as a whole. Believers may call it the "end of the world" or "end times".
Eschatologies vary in optimism or pessimism about the future. In some eschatologies, conditions are better for some and worse for others, e.g. "heaven and hell". They also vary as to time frames. Groups claiming imminent (soon to come) eschatology are often called doomsday cults.