In XperienCentral, the term "page section" refers to content that can be shown on multiple content items and at different locations on those content items. When implementing custom code handling or manipulating page sections, it is important as a developer to be aware that the name for the page section concept in XperienCentral was previously referred to using the term "block". This old term can still be found in several interfaces, classes and class members in the XperienCentral code base.
While the terms "page section" and "block" are synonymous in the XperienCentral terminology, we encourage you to use the term "page section" in your custom code where possible.