That is a big part of the fun of tiddlywiki that is so much fun, the many things a tiddler can be. In some ways I think it is a good reason to continuing to call it a tiddler because by not committing it to one of these meanings, it can have any of these meanings.
To me it is quite profound how a tiddler is a “record” in file and database terms that, can be, be related to, or part of, any number of tables, lists or sets.
Yet a single tiddler can always be its own thing, sitting at eye level and mean almost anything to us.
But even such a versatile thing as a tiddler has secrets waiting to be discovered. Consider for example a link to a non existing tiddler, a missing tiddler is still content, it can be a tag, a value in text or a field and have relationships with other tiddlers even before it exists.
Even before a tiddler exists, it can be found. Even defined, by its relationships and context.
Mind blowing