Category boundaries are what separates categories from each other. Thus category boundaries are lines of demarcation between what is inside the category and what is outside the category.
In the Aristotelian model of categorization, boundaries are clearly delimited, and their boundaries clear-cut and fixed, whereas in Cognitive Linguistics and related disciplines, categories are less clear-cut and have what is called fuzzy boundaries.
- Croft, William A. & D.A. Cruse (2004). Cognitive Linguistics. Cambridge: Cambridge University Press.
- Ungerer, Friedrich & Hans-Jörg Schmid (1996). An Introduction to Cognitive Linguistics. London: Longman.