Chapters 7 and 8 are not in chronological order. They happened while Belshazzar was still the king, before the rule of Darius and Cyrus that was discussed in chapter 6. In Daniel's vision, he saw animals that were symbols of other things. Later in the vision someone explains the meaning of those symbols. (See: [[rc://en/ta/man/translate/writing-symlanguage]])
The words "dream" and "visions" both refer to the same dream that is described in this chapter. Alternate translation: "visions while he was dreaming" (See: [[rc://en/ta/man/translate/figs-doublet]])