Difference between folder and group in Xcode?

Question

In Xcode, what is the difference between a folder and a group? Are these interchangeable terms or is there a subtle difference?

Answer 1

Groups

With groups, Xcode stores in the project a reference to each individual file.

Folders

Folder references are simpler. You can spot a folder reference because it shows up in blue instead of yellow.

There are two types of folders in Xcode: groups and folder references. You can use groups to organize files in your project without affecting their structure on the actual file system. This is great for code, because you’re only going to be working with your code in Xcode. On the other hand, groups aren’t very good for resource files.

On any reasonably complicated project, you’ll usually be dealing with dozens – if not hundreds – of asset files, and those assets will need to be modified and manipulated from outside of Xcode, either by you or a designer. Putting all of your resource files in one flat folder is a recipe for disaster. This is where folder references come in. They allow you to organize your files into folders on your file system and keep that same folder structure in Xcode.

Reference

Answer 2

A folder in Xcode represents a folder in the file system.

A group in Xcode is a "fake" folder which does NOT represent a folder in the file system.

It is common to use a combination of groups and folders for a given Xcode project.