Note is a central entity in Trilium. Main attributes of note are title and content.

• text note - this is default note type which allows you to put rich text, images etc.
• code note - some kind of formal code, typically programming language (e.g. JavaScript) or data structure (e.g. JSON)
• image note - represents single image
• file note - represents uploaded file (e.g. docx MS Word document).
• render HTML note - this works as an output screen of attached scripts
• saved search note - contains saved search query and dynamically displays result of the search as its sub-notes
• relation map note - visualizes notes and their relations
• book note - displays its children notes, useful for reading many short notes
• mermaid - create diagrams and flowcharts using mermaid.js ↗
• canvas note - allows hand drawn notes and basic diagraming on an infinite canvas using excalidraw ↗

In Trilium there's no specific "folder" note type. Any note can have children and thus be a folder.

There's one special note called "root note" which is root of the note tree. All other notes are placed below it in the structure.

Importantly, note itself doesn't carry information on its placement in note tree. See cloning for details.

Tree structure of notes can resemble file system - but compared to that notes in Trilium can act as both file and directory - meaning that note can both have its own content and have children. "Leaf note" is a note which doesn't have any children.

When you delete a note in Trilium, it is actually only marked for deletion (soft-delete) - the actual content, title, attributes etc. are not deleted, only hidden.

Within (by default) 7 days, it is possible to undelete these soft-deleted notes - open Recent Changes dialog, and you will see a list of all modified notes including the deleted ones. Notes available for undeletion have a link to do so. This is kind of "trash can" functionality known from e.g. Windows.

Clicking an undelete will recover the note, it's content and attributes - note should be just as before being deleted. This action will also undelete note's children which have been deleted in the same action.

To be able to undelete a note, it is necessary that deleted note's parent must be undeleted (otherwise there's no place where we can undelete it to). This might become a problem when you delete more notes in succession - the solution is then undelete in the reverse order of your deletion.

After the 7 days (configurable) the notes will be "erased" - their title, content, revisions and attributes will be erased, and it will not be possible anymore to recover them (unless you restore backup).

• Read-only note