What is maya?
In avaita Vedanta the world we naturally perceive before enlightenment
is called maya. Maya entails the sum of one’s perceptions about one’s
self and the world--the way we see the physical appearance of the world,
our beliefs, culture and psychological state. Maya can be translated
as "illusion," but this word fails to portray one’s own involvement in
creating the state. It is both illusion and delusion. Coming
from the same root as the word "magic," maya suggests that people are tricked
by their perceptions. People assume that their finite aspects--e.g.,
their personality and appearance, their culture and values--actually represent
their true identity. In truth, however, these are simply mirages
perpetuated by habit and lack of self-knowledge. The true nature
of reality, Hinduism asserts, is a vast unity that reaches far beyond this
chimeric mask.
Another definition:
maya (mä´ye) noun
Hinduism.
The transitory, manifold appearance of the sensible world, which obscures
the undifferentiated spiritual reality from which it originates; the illusory
appearance of the sensible world.