Target
A Target is both a relational and a functional entity in that it ties things together and it provides a function of its own. A target is used to represent a site or subsite, and acts as the glue that binds content to its destination(s).
Most of the time one target will be created to represent a website, with subtargets (children nof the master target)created for the different templates within that site (html, xml, handheld, etc.) By defining a base folder (the main folder that contains all the content for the site), the "master" target ties together the entire site - all the subtargets and their templates. Each subtarget ties an individual site template (xml, for example) to the pages (and the pages' related files) that use that template.