How to save a .CXR file from the VFB
After rendering is complete, long press on the save button in the VFB. This will bring up two options: Save All and Save CXR
The benefits of being able to save in this format will allow you to resume a render or add post-processing data later on.
Saving multiple .CXR's is also possible. This could come in handy if you are rendering an animation or image sequence.
How to save multiple .CXR's?
In the Corona drop-down menu, select preferences and on the pop-up window towards the bottom turn on Automatic saving on render end.
Now an image will be saved after each render has completed it's desired passes, set noise limit reached, or if it's stopped manually.
By default images saved in the history will be stored in:
C: > Users > yourpcname > AppData > Roaming > MAXON > Cinema4DR(yourversion) > corona > history
For more information about resuming a render, see: How to pause and resume rendering with Corona Renderer for Cinema 4D?