What is the difference between an 'EPERM' error and other file system errors in Node.js promises?

An 'EPERM' error specifically relates to a lack of operating system permissions to perform the requested operation. Other file system errors might indicate different issues: 'ENOENT' means 'No such file or directory', 'EBUSY' means the resource is currently in use, 'EISDIR' means the target is a directory when a file was expected, and so on. EPERM is distinct because it directly points to a privilege or permission deficiency at the OS level.