Tiddlers are the smallest unit of information in TiddlyWiki. Other systems have analogous concepts with more prosaic names: like "items", "entries", "entities" or "records". Even though "tiddler" is a vaguely preposterous name it at least has the virtue of being confusingly distinctive rather than confusingly generic.
Tiddlers can be structured with links and tags.
Internally, tiddlers are an immutable dictionary of name:value pairs called fields. The only field that is required is the
title field, but useful tiddlers also have a
text field, and some or all of the standard fields listed in TiddlerFields.