Our universe is one of the many universes in the material world. According to scriptures, the spiritual world has been calculated to comprise three-fourths of the energies of the Supreme Lord, and the material world is said to comprise one-fourth of His energy, but no one can understand what this three-fourths is, since even this material universe, which comprises only one-fourth of His energy, cannot be described. Our universe is only four thousand million miles broad; however, there are many millions and billions of universes which are far, far greater than ours. Some of these are many trillions of miles broad.
Beyond the material sky, there is an unlimited span of spiritual sky generally known as the brahmajyoti. Within this effulgence there are innumerable spiritual planets, and they are known as the Vaikuntha planets. Each and every Vaikuntha planet is many, many times bigger than the biggest universe within the material world, and in each of them there are innumerable inhabitants who look exactly like Lord Viṣṇu. These inhabitants are persons directly engaged in the service of the Lord. They are happy in those planets and are without any kind of misery, and they live perpetually in full youthfulness, enjoying life in full bliss and knowledge without fear of birth, death, old age or disease. (Bg. 1.14.35–36, Purport) In those planets there is no difference between the body and the soul, nor is there any influence of time as we experience it in the material world. (Bg. 2.5.39, Purport).
Source: A.C. Bhaktivedanta Swami Prabhupada (2012 edition), “Teachings of Lord Caitanya, The Golden Avatara”, Page 113 and 114.
Urmila Devi Dasi, http://btg.krishna.com/creation-and-dissolution-material-world, Last accessed on July 03, 2016.