Druids had two ways of entering the Emerald Dream. One was to dream their way in.
Put simply, anywhere in the Warcraft Multiverse, they could find a spot to lie down and sleep, and there was a certain chance they would dream of entering the Emerald Dream. They might become a Butterfly, or perhaps a rabbit—some animal found in nature—frolicking to their heart's content in a fresh, pure natural environment.
Most Druids chose this method, because life in dreams was simply too wonderful and carefree. They had no desire to wake up at all, which was why so many Night Elf Druids ended up in a "Vegetative State."
Their bodies still slept on Azeroth, but their souls were gone. They played another carefree role in the Emerald Dream, getting as close to nature as they possibly could.
Because they loved nature too deeply, most Druids believed dreaming was far happier than being human. Even the air in the beautiful Emerald Dream was so fresh—it was far better than the Azeroth where they had grown up! They had no wish to return. Just mentioning Azeroth made them feel Disgust.
Thus, they became completely immersed in dreams, drawing energy from them to nourish their physical bodies so they could sleep endlessly, or even abandon their flesh and fully merge with nature.
The reason it was called the Emerald Dream rather than the Emerald Dimension or Emerald World lay precisely in this.
Its essence was the same as Dream's Dreaming: void and nonexistent. It had been constructed by the collective dreams of nature's living creatures—the dreams of flowers, trees, insects. Any creature that lived in and loved nature contributed power to this peculiar dream.
Su Ming felt there would be nothing wrong with calling it the Dream of Nature or the Dream of