Myth: The orb web (the round, spiral or "geometric" type of web) is a "normal" spider web.
Fact: Although orb webs are the most conspicuous webs (because they tend to be large and are often suspended in mid-air) they are not at all the most common type. In temperate regions, sheet webs are by far the most common, and cobwebs are also more abundant than orb webs. In some locations, funnel webs are also more common. Only in the tropics can orb webs equal other web types in abundance, but they still are rarely in the majority. So when you notice a spider web that is not a round orb, rest assured that it's perfectly normal.
Examples of 4 major types of spider webs.
Each functions somewhat differently in prey capture. Sheet webs and funnel webs have no sticky silk.