You can export or import schema definitions using the Export/Import tab in the schema editor.
Export files are JSON files representing the whole schema data. When importing a schema into an existing schema that already has columns, those columns will be overwritten! To match columns between the existing schema and the ones in the JSON, the internal colref IDs are used (those reflect the order in which columns where originally created).
When importing a schema with localized labels into a wiki that does not have the same languages, all labels for unknown languages will be ignored.
See also: