Aspose.Words API provides several classes responsible for different document elements’ formatting. Each of the classes encapsulates a number of formatting properties related to a particular document element such as text, paragraph, section, and so on. For example, the Font class represents character formatting properties, the ParagraphFormat class represents paragraph formatting properties etc. The objects of these classes are returned by the corresponding DocumentBuilder properties (that have the same names as the classes) so you can access them and set desired formatting during the document build.