The lower realm of pleasures are material pleasures, which in Indian Mythology is the stage that deities could reach. [That’s why they had to go for help from God (Vishnu or Mahadev or Brahma – The Trinity of Gods) or Supreme Power (शक्ति)(Durga, Kaali or Ambaa) when they failed to overpower some of the very strong demons]. This is known as Paradise.
Whereas Heaven is where material pleasures have no significance. One raises a few notches to renounce all material (sensory)pleasures(माया) and reach the stage of ब्रह्म.
The article has differentiated both with the help of a telling example.