The Quick Collection is the equivalent of a scratch pad. You can add group of photos, delete, change/process, keywords…

The Quick Collection is the collection with the + after it, it doesn’t have to be the collection named Quick Collection.

Screen capture of Lightroom: Quick Collection panel

  • B will add the selected photo or photos to the target Quick Collection.
  • Control (Mac) or Right Mouse (Windows) and click any regular collection will change the status to Set as Target Collection.
  • Command + Option (Mac) + B or Control + Alt (Windows) + B will convert the Quick Collection into a regular collection.
  • Command (Mac) + B or Control (Windows) + B shows the contents of the Quick Collection.
  • Command (Mac) + Shift + B or Control (Windows) + Shift + B will empty the Quick Collection. It doesn’t delete the photos from the All Photographs just from the Quick Collection.
  • Command (Mac) + Z or Control (Windows) + Z will undo the last operation (just in case you you emptied the Quick Collection by “accident.”)