isr.co.ro : glossary Open As applied to computer systems, built around published specifications available to any manufacturer who chooses to compete. As applied to documents and files, ready to receive or supply information. In most systems, before information is read from a file or written to it, the file must first be "opened" so the operating system can assign the resources required to manage the process. As applied to the state of an object in a visual interface, shown in an expanded format that displays the contents or state of the object.