The Mirror of Erised is a magical mirror, that shows ones deepest and most desperate desire of their hearts. Albus Dumbledore tell Harry Potter that the happiest man on earth would look into the mirror and see only himself exactly as he is
When Harry first found the mirror of erised he saw some writing written across the top of the frame:
Erised stra ehru oyt ube cafru oyt on wohsi
Backwards this says:
I show not your face but your hearts desire
The Mirror of Erised was hidden by Albus Dumbledore in an unused classroom, where no one would hopefully find it. Although the mirror seems good and fascinating, it actually causes great danger.
"Men have wasted away before it, not knowing if what they have seen is real, or even possible.!
-Albus Dumbledore to Harry Potter on the mirror of Erised.People who do not know the mirrors purpose could waste away before it, just as Dumbledore said. Ron Weasley did not know the purpose of the mirror and thought it to show the future. If it hadn't been obvious that it didn't show the future, as when Harry stood in front of the mirror it showed him his parents, who only esisted in the past, Ron may have gone back to the mirror to try to work out if what was in the mirror could become possible in any way. Harry Potter went back to the mirror for several nights in a row, so that he could see his parents and other members of his family. This made Harry happy, that for the first time he could visit his parents. Even though he couldn't converse with them, he still loved to just sit there and watch them. Albus Dumbledore had being watching Harry for several nights and found it wise to remove the mirror to a safer place. He told Harry not to go looking for it an not to request to see it. Harry then asked Dumbledore what he saw when he looked into the mirror. Dumbledore said that he saw himself holding a pair of socks, Harry didn't beleive this, but decided not to question it further. In 1992, the mirror was the final obstacle guarding the Philosophers Stone. Proffesor Quirrel was after the stone for Lord Voldemort. Once Quirrel had past all the other obstacles gaurding the stone, he reached the mirror. He saw himself presenting the stone to Voldemort, but did not know how to retreive it. Once Harry Potter had reached the mirror, he saw the Philosophers stone drop into his pocket. The next second the Philosophers stone was actually in his pocket. This was because anyone that wanted to find the stone, find it, but not use it, would be able to get it.