The book of Revelation gives its name to a category of literature that signifies a vision of heavenly things. The book of Revelation is John’s vision of the end of human history as we know it. It begins a new reality in the kingdom of God. Generally, people view Revelation as an apoplectic story, however, it does not necessarily reference the end of the world.
Revelation could be placed into three categories: an apocalypse, prophecy, and a letter. Apocalyptic stories typically contain symbolism, heavenly journies, and angels. Revelation can be categorized as a prophecy as it is telling of what will happen in the future. It can also be categorized as a letter because it is written to a specific group of people. Revelation is written as one letter to seven different churches however, each of them is singled out at one time within the story.
Revelation is about the future, however, it is not determined whose future it is referencing. It could only be the future of these specific churches or it could be the future of all of Christianity. It also references the present. People have many different approaches to interpreting the book of Revelation.