文件类型规范：各种数据文件类型。数据文件的扩展名是用于在Linux / Unix / MacOS的数据文件的操作系统（OS X）。用于各种应用。数据文件通常包含用于应用程序内部目的的各种数据，它不能被打开。(File type specification: Various data file type. The data file extension is used for data files at Linux/Unix/macOS (OS X) operating systems. Used by various applications. .data files often contain various data for internal purposes of applications, it cannot be opened.)