Adding a folder name to each contained file involves automatically renaming every file within a specific directory by inserting the name of that directory into the beginning of each filename. This differs from simply renaming one file or manually adding prefixes, as it performs the task in bulk for all files within the folder. The process leverages a capability called batch renaming, found in file explorers and dedicated utilities. You typically specify the target folder and a renaming rule that incorporates the folder's name.

For example, you might rename photos in a folder "Vacation_2024" from "IMG_1234.jpg" to "Vacation_2024_IMG_1234.jpg". Similarly, research documents in a folder "Project_Tiger" could change from "SurveyResults.pdf" to "Project_Tiger_SurveyResults.pdf". This is frequently done using built-in features in file explorers like Windows Explorer (using the Command Prompt/PowerShell or PowerRename), macOS Finder (with Automator or Terminal), Linux shells (Bash), or dedicated file management tools like Bulk Rename Utility.

This method significantly improves file organization by embedding the source context directly into the name, making it easier to identify file origins when files are moved or shared. It is particularly beneficial for archiving and cataloging large collections. However, the main limitation is potentially creating very long filenames, especially with nested folders, which might exceed system limits or become unwieldy. Using it carelessly can also break applications relying on exact filenames.