The offline editing plugins is a default plugin that ships with QGIS and allows you to offline a remote dataset (e.g. from a database), edit it in the field, and then resynchonise it when you get back to your office. This extends the offline editing possibilities to only work on subset of large layers.
This feature was funded by DB Fahrwegdienste GmbH
This feature was developed by Matthias Kuhn (OPENGIS.ch)