Web says :
If the webs aren't anchored between two solid masses (such as walls or trees) OR layered across a floor, wall, or ceiling, the conjured web collapses on itself, and the spell ends at the start of your next turn. Webs layered over a flat surface have a depth of 5 feet.
I'm having difficulty imagining webs not attached to something. Are they stacked up like pancakes? Does this mean I can just throw webs on the ground and not worry about attaching them to something? What are the disadvantages/advantages of anchoring/not anchoring? Or should the "or" in web be an and?
This is similar How exactly does the Web spell work? but I'm asking about 5th ed not pathfinder. The wording is very different.