Winding order
Winding order refers specifically to the "direction" that a polygon's rings go in. This has several different and conflicting definitions, which you can find some discussion of in the following articles:
GeometryOps assumes that polygon exteriors are clockwise and interiors are counterclockwise. However, most algorithms are agnostic to winding order, and instead rely on the GeoInterface getexterior and gethole functions to distinguish holes from exteriors. Notably, most GIS implementations agree that polygons can have only one exterior but several holes.
What other libraries do
TODO: Markdown table with a bunch of libraries/standards, their winding orders, and references.