Answer
Sep 11, 2012 - 08:10 AM
Category IDs define exactly what category, under what hierarchy structure, is being referenced. This Category ID is used when referencing or defining categories when placing widgets on your website or when utilizing the API.
For example, if one of your category Hierarchies is this:
Food > Vegatables > Carrots
Lets also say that "Carrots" has the Category ID of 35. In the case where you're looking to define what category a widget's content is associated with, and you're able to define a Category parameter within that widget, if you identify 35 as the parameter it would automatically associate that content that is under that exact category string "Food > Vegetables > Carrots" but just defining the ID 35 which is associated with the category "Carrots". All root categories are automatically associated
