Using ArcMap, it is possible to add a dataset (eg a shapefile) to the map, and configure the layer's properties (such as the symbology, table joins, switching some attributes off in the Identify results, etc).
This layer can then be saved as a Layer file:
The resulting *.lyr file references the data source (the shapefile) and all of the properties which have been configured for that layer. This makes it easy to add this same layer to multiple map documents, inheriting all of the properties which have been set.
Is there an equivalent in QGIS?