What's are the files with names beginning with ._ in my project folder?

In my project folder some projects have another extra file using the same name except for the extra files having ._ in front of them. These files are usually only a few KB in size while my projects usually range from 300-500KB. Do they server some kind of backup purpose or what are they?

That has nothing to do with Dorico or Steinberg, that’s an Apple file system thing: https://apple.stackexchange.com/questions/14980/why-are-dot-underscore-files-created-and-how-can-i-avoid-them#answer-51147

Oh, I knew about the .DS_Store files but not these other ones. Have an older Mac Book that I basically only use for Dorico so I’m not very knowledgeable when it comes to Mac. Thanks for the answer!