First, a pet peeve. The book is not titled Revelations (plural), it is Revelation, as in “The Revelation of Jesus Christ” (vs. 1). The term “revelation” is taken from the Greek “apokalypsis”, and literally means an unveiling.
What is contained in this book is the Revelation of Jesus Christ, sent to the apostle John by way of a vision. John asserts that what he writes in the book is a faithful testimony of “all things that he saw” (vs. 2).
As John pronounces a benediction upon “he who reads and those who hear”, and “keep those things that are written” in this Revelation, he indicates that the vision in the book concerns events that would soon occur. Note the two phrases: “things which must shortly take place” (vs. 1), and “the time is near” (vs. 3).
The book of Revelation contains many symbols. The style of writing has been referred to as “apocalyptic language,” and requires careful interpretation. It is important to note that the method of interpretation used to successfully divine the meaning of Revelation takes into consideration that the book was written to Christians in that day concerning events which would “shortly take place.”