Authors have a range of options to choose from when organizing a collection of wiki pages.
Used in combination, these give a lot of flexibility.
An effective wiki will use all of these to optimize

• content
• navigation

These are the two most important aspects of a website.

Wiki Word

The most powerful organizing principle is the author's choice of page names. When a search returns a list of pages, their names need to be clear enough to guide a visitor to the right place.

Providing a network of links to other points in the wiki, with or without wiki words, is the primary means of navigating a wiki.

Wiki Page

A page with text (and images), where the text can contain for instance WikiWords that automatically becomes a link to another WikiPage.

Wiki Group

PmWiki requires every page to be a member of a group. A group is like a wiki within a wiki; it can have its own presentation look, security controls and navigation aids. With default configuration, WikiWords are only searched inside the current group, and you use either OtherGroup/MyWikiWord or OtherGroup.MyWikiWord to refer to pages in other groups (see Links).

Wiki Trails

A collection of pages, either in the same group or across multiple groups, can be designated as a trail. A visitor can move from stop to stop by clicking on next and previous links.

Categories

Individual wiki pages can also be grouped by having tags and links to a common "category" page; we say that any pages that link to a common page are in a "category" defined by that page. PmWiki uses the [[!category]] markup as a shorthand to place a page into a category with other pages containing the same markup.

The shortcoming of categories is that categories do not distinguish between the declaration of a category ([[!structure]]) and the link to a category ([[Category/Structure]]).

Page text variables

A newer and more powerful concept than Categories, pages can use one of more page text variables to store page attributes. These can the be used in page lists.

Page lists

Page lists provide a powerful means of presenting lists of relevant pages, or selection of data from within a page. Lists are template based and are highly customizable.

Include other pages

The capability to include parts of other pages also provides a flexible means of sharing content between pages.

Search

Being able to search is a fundamental requirement of a website. In PmWiki search, like pagelists is both powerful and highly customizable.