It is said yA mA sA, meaning that that which is not is Maya. But when not a negative definiton, Maya is said to be Ishvara's shakti or at other places, as a universal avidyA as seen in contrast to individual jIva avidyA. With the latter explanation, jIva is under the influence of avidyA while Maya is under the control of Ishvara. In further detail, Maya is described as having two aspects in the form of powers: AvaraNa (concealing) shakti and vikshepa (projecting) shakti. The AvaraNa conceals the svarUpa of brahman for the jIva, while the vikshepa projects this jagat. Under the influence of avidya, jIva dances with vikshepa jagat and goes through countless janma-mRtyu cycles. With these fundamentals in the background, I present a premise herewith: AvaraNa is the cause for vikshepa. How so?
Suppose a table upon which you place a thing known to you, but unknown to me. Further, you conceal it with an opaque cloth so that I can't see what it is, let alone know it. That is Ishvara's AvaraNa of brahman, causing jIva's ignorance of his own svarUpa. Then, whether or not you ask me, I start guessing and deluding what is it that is concealed underneath, based on what I consider to be its outward shape, giving rise to several forms. Those, I start naming as per my own association of things or such. Over a period of time or all at once, I'd end up projecting several things. That is Ishvara's vikshepa of jagat. In this play, someone pulls off the cloth or somehow the thing concealed is revealed to me. I'd suddenly lose the ignorance of the thing, gaining the knowledge of it. With that event, what would happen to all those deluded things projected? Or what would happen if you or I start discussing as to what all things it looks like? Nothing in particular would happen of the nature of ignorance again. I may still play along, but all the while having the knowledge of the thing revealed unto me and not get deluded with projections of different forms and names. Ergo, if Ishvara were not to use AvaraNa shakti to conceal my svarUpa, I'd never get deluded by his vikshepa shakti. In other words, you cannot tell me the truth and then make me believe in lies.