In case you're serious about not understanding it and revisit this: It allows you to drag and drop files into an interface to rename them according to a patter

In case you're serious about not understanding it and revisit this: It allows you to drag and drop files into an interface to rename them according to a pattern you've provided. Or to drag and drop files into an interface to optimise them for size. Or to drag and drop files into an interface to do mostly anything. All of the actions are plugins. Basically, it's a desktop app (for Mac/Linux/Windows) that accepts drag-and-dropped files to perform your chosen actions, like renaming, optimizing, etc.