Bhagwan Krishna and Narada were going in a forest. After travelling a distance, Krishna felt thirsty. He asked Narada to fetch Him water. Narada went immediately to get water.
Narada reached a village nearby and knocked the door of a house and it opened. Behind the doors stood a beautiful lady, with attractive eyes. She was equal to celestial Ramba in her beauty. She enquired in her sweet voice, "who is knocking the door?" Narada, on seeing the beautiful lady, forgot the purpose of his visit. He talked various things about love but did not whisper about water. Sun began to set, yet Narada was going on with his conversation with the lady. Narada stayed in that village that night. Next day, he visited that lady and he became very friendly with her. Days rolled on. The Magnet, attracted the needle well. Love blossomed. It ripened and ended in a marriage. They led a pleasant married life and three children were born to them. Thus 12 years passed and father of the lady died. Narada got his properties too. He was very happy.
Later, on a day, there was a big flood. The river broke its banks and the village got immersed in water. Cattle persihed. Men and women were washed away by the floods. Narada wanted to escape with his wife and children. Both took the children and crossed the floods. The child on the shoulders, slipped into the water and washed away in the floods. Narada wanted to save the child from the floods and in that process, let the remaining two children out of his hold and they were also washed away. He cried aloud and held his wife firmly fearing that she will also be washed away by the floods. The floods, fury did not abate and washed away his wife also. Narada was left alone. He cried to his breath and was totally shaken.
At that time, a hand touched his shoulders from behind. Narada turned and there he saw Bhagwan Krishna. He asked Narada "What happened to you. Where is water. I have been waiting for you over half an hour".
Narada replied expressing surprise: "Krishna, I had spent 12 years now after leaving you, and my mind tells me so. How is it that all these happened in half an hour ? Krishna replied smilingly "Narada, once you asked me what "Maya" is? Now you understand what it is. That is 'Maya'.
"Yama Sa Maya". That which is not is Maya. Brahmam alone exists. In other words 'THAT WHICH EXISTS IS BRAHMAM'. The rest is illusion or 'Maya'. Narada understood what is permanent or Nithya Vasthu.
Adhi Shankara says that 'Maya' is "ANIRVACHANIYAM" (Cannot be expressed). It is neither "Sath" nor "Asath" ( Neither Truth or Untruth ). Whether exists or does not exist. When the shell twinkles, one feels for a moment that it is silver. When he goes near to that, he finds that was an illusion. A rope is mistaken for a snake when viewed from a distance. On going near it, you get the knowledge of its true nature. Mirage is also comes in the above line. Even for a person who knows that Mirage is not water, yet he sees water in Mirage.
In all the above examples, once you get the true nature of things, you get to understand that what you said earlier was an illusion or untruth. If the original appearance is fine, it should remain the same all the time. It is not so.
Therefore the eternal truth is 'PARAMARTHIKA SATHYAM'. 'Vyavaharika Sathyam' is one in seeing appearance as true in day-to-day life. 'PRATHIPASIKA SATHYAM' is appearance of certain things as true for a short period. Once you get true knowledge both Vyavaharika and Prathipasika Sathyams will reveal as illusions.
In the example given above, 'SNAKE' is 'AROPYAM', 'ROPE' is 'ATHISHTHANAM'. If Athishthanam becomes true, Aropyam will disappear. We think that this world, which is a Vyavaharika Sathyam as true and on gaining true knowledge, this Vyavaharika Sathyam will disapear. So long as you live in the material world, the world is really true. Once you get the vision, the world will become an illusion.
Sadhguru Gnanananda explains easily 'Maya' thus :
"There is no answer as to where and how this 'Maya' came to existence. If you ask darkness as to how it came, it will not disappear. You bring a light, then darkness goes. It is not possible to enquire into the origin of Maya. Once you get light, the darkness of ignorance disappears. It should come to you of your own experience and effort'.