title: Wiki
tags: docs concepts

Groups of uniquely titled tiddlers are contained in WikiStore objects.

The WikiStore also manages the plugin modules used for macros, and operations like serializing, deserializing, parsing and rendering tiddlers.

Each WikiStore is connected to another shadow store that is used to provide default content. Under usual circumstances, when an attempt is made to retrieve a tiddler that doesn't exist in the store, the search continues into its shadow store (and so on, if the shadow store itself has a shadow store).

!! ~WikiStore Events

Clients can register event handlers with the WikiStore object. Event handlers can be registered to be triggered for modifications to any tiddler in the store, or with a filter to only be invoked when a particular tiddler or set of tiddlers changes.

Whenever a change is made to a tiddler, the wikistore registers a `nexttick` handler (if it hasn't already done so). The `nexttick` handler looks back at all the tiddler changes, and dispatches any matching event handlers. 