A Property Editor is the editor that a Data Type references. A Data Type is defined by a user in the Umbraco backoffice and references a Property Editor. In Umbraco a Property Editor is defined in a JSON manifest file and associated JS files.
When creating a data type, you specify the property editor for the data type to use by selecting from the "property editor" list (as shown below)
Umbraco comes preinstalled with many useful property editors...
- How to create a Property Editor Creating property editors for Umbraco