From OrganicDesign Wiki
The sections of an article are the areas of text divided up by headings (using == wikitext notation). Each section can be individually edited which is more efficient in terms of traffic, organisation and edit conflict prevention.
The text before the first heading is called "section zero", and should contain a summary of the entire article as is the convention on Wikipedia. In the case of articles which are of a particular structured "kind" it's organisational template should be the only content of section zero.
Example
{{#dpl:category=foo|include=%0|listseparators=,,}}
