Random 'concerns' folders and '.keep' files

Question

I am learning rails.

Somewhere along the line, I noticed that seemingly random folders and files are appearing in my rails app's directory. In some folders there is a concerns folder with a .keep file inside it. The .keep file appears to be empty. In other folders there is no concerns folder but an empty .keep file is present.

Does anyone know what the deal with these files/folders is?

Answer 1

.keep files are 0 byte files that are there to stop empty folders from being ignored by all sorts of processes. Nothing to worry about.