Daniel said the God of heaven would set up a kingdom that will never be destroyed. This kingdom would break in pieces the other kingdoms and stand forever, pictured by the stone that became a great mountain. Daniel 2:44–45
Daniel explains the king’s dream as a sequence of world powers: Nebuchadnezzar is the first, pictured as gold, and after him come three more kingdoms with changing strength and unity. The final human kingdom is both strong and fragile, unable to hold together. This passage is the explanation stage of the larger scene where Nebuchadnezzar demands both his dream and its meaning. Daniel has already credited the revelation to the “God of heaven,” not human skill, and has described the statue dream (gold head, silver, bronze, iron, and mixed feet) and the stone that strikes it.
Daniel presents history as a sequence of real human kingdoms that rise and fall under God’s oversight. Nebuchadnezzar’s rule is great, yet it is described as given by “the God of heaven” (verses 37–38). After him, other kingdoms come in order, differing in strength and cohesion (verses 39–43).
A careful answer keeps the immediate passage, the book's argument, and the whole-Bible storyline together, so the question is answered in context instead of as a detached idea.
Start with Daniel 2:44-45, then read the surrounding section so the answer stays connected to the passage's flow.
44In the days of those kings shall the God of heaven set up a kingdom which shall never be destroyed, nor shall the sovereignty of it be left to another people; but it shall break in pieces and consume all these kingdoms, and it shall stand forever.
45Because you saw that a stone was cut out of the mountain without hands, and that it broke in pieces the iron, the brass, the clay, the silver, and the gold; the great God has made known to the king what shall happen hereafter: and the dream is certain, and the interpretation of it sure.