When you double-click a file on your computer, Windows may launch an application to run or display the file. Windows knows how to do this because it maintains a list of known file types and the names ...

Red Eye Rose received a file with a strange extension. She doesn’t know into what program she should load it. Neither does Windows. I doubt that anyone knows all of the file extensions used since the ...

Back in the pre-Mac OS X and macOS days, Apple’s System 9 and earlier relied on hidden metadata to associate files with apps. File extensions, those bits of text that follow a period at the end of a ...