The Web, while similar to The Lattice
in both origin and and total omnipresence throughout all of reality, is considered a different aspect of reality inherently linked to and representing fate. It is a thing wholly distinct from @Lattice, though only the gods are generally skilled enough to distinguish it from The Lattice in which it is believed to hide in and masquerade beneath...although some mortal magics touch upon the web to alter the threads of possibility, direct manipulation is all but impossible. Each creature in the Planescape, even the divine, are said to be bound to The Web, and it is from this likeness from which it draws its name. Each creature possesses a "string" that connects them to this web, and represents the entirety of their fate and their destiny...even the gods have these "strings".
Nature of The Web
Generally, the stronger the creature, the thicker the "string" and the harder it is for themselves or another, even the gods, to infringe upon their fate...and taking this idea to the logical extreme, the notion of accessing and manipulating the strings of The Gods or divine beings is so herculean none are believed to be capable of it...however, a rare few individuals have proven capable of manipulating such connections on a mortal scale to alter the future to their advantage. However, usually The Web punishes those who use "her" in such a way.
The Web is managed and overseen by the Yema Goddess Lolth, The Spider Queen
, who has retained the role since her inception and even through her eventual fall into evil. She has retained mostly the same degree of impartiality throughout the eons, and is believed to be as much bound by the web as it is to her. It is her who spins each creature's "string" of fate that connects them to this web, and her who manages The Web to strike out at those who dare to manipulate it for their own ends.
However, as much as the Yema Goddess might oversee and manage the web, it is believed that Xu-Jie
is a fundamental part of The Web(at least partially), as a physical manifestion of many things, fate included, and so works to balance out the Yema Goddess managing it to ensure fate has no biases.