Who is The Witch from The Complete Fairy Tales of the Brothers Grimm and what is their importance?

The witch actually appears in different tales. These witches generally disguise themselves in some less evil form to lure their prey and then reveal their true nature. This occurs in the story "Hansel and Gretel", where the witch pretends to be a kind old woman until she has the children in her grasp. These witches are generally known for their cruel nature; however, other characters seem to find it hard to stay away from these witches.