If you want to edit several photos with one plugin, you can do it in batch mode. Batch processing lets you quickly edit multiple images with minimal effort.
If you do batch processing in plugins performing automatic correction (Fix Red Eye, Color Correction and Denoise), processing is fully automated - you just select photos and the desired plugin.
In case of manual correction, batch processing is done in "one by one" mode but offers a timesaving and convenient way to handle files: you edit images one after another without interrupting to open each next file.