Maya, in Hinduism, is many things. It encompasses the ideas of a state of 'skewed perspective' (not quite illusion), a creatrix energy (prakriti) and a personified goddess.

Maya in Hindu philosophy

In Advaita Vedanta philosophy, maya is the illusion of a limited, purely physical and mental reality in which our everyday consciousness has become entangled, a veiling of the true, unitary Self, also known as Brahman. Maya originated in the Hindu scriptures known as the Upanishads. Many philosphies or religions seek to "pierce the veil" in order to glimpse the transcendent truth, from which the illusion of a physical reality springs, drawing from the idea that first came to life in the Hindu stream of Vedanta.

In Hinduism, Maya must be seen through in order to achieve moksha (liberation of the soul from the cycle of death and rebirth) - ahamkar (ego-consciousness) and karma are seen as part of the binding forces of Maya. Maya is seen as the phenomenal universe, a lesser reality-lens superimposed on the one Brahman that leads us to think of the phenomenal cosmos as real.

Maya as the Goddess

In Hinduism, Maya is seen as the illusory form of Devi, the Divine Goddess. Her most famous explication is seen in the Devi Mahamaya, which is said to spring from the Devi Sukta passage of the Vedas.

Essentially, Mahamaya (great Maya) both blinds us in delusion (moha) and has the power to free us from it. Maya, superimposed on Brahman, the one divine ground and essence of monist Hinduism, is envisioned as one with Kali, Durga, etc. A great modern (19th century) Hindu sage who often spoke of Maya as being the same as the Shakti principle of Hinduism was Shri Ramakrishna.

In the Hindu scripture 'Devi Mahatmyam,' Mahamaya (Great Maya) is said to cover Vishnu's eyes in Yoganidra (Divine Sleep) during cycles of existence when all is resolved into one. By exhorting Mahamaya to release Her illusory hold on Vishnu, Brahma is able to bring Vishnu to aid him in killing two demons, Madhu and Kaitabh, who have manifested from Vishnu's sleeping form. Sri Ramakrishna Paramahamsa often spoke of Mother Maya and combined deep Hindu allegory with the idea that Maya is a lesser reality that must be overcome so that one is able to realize his or her true Self.