When you save a document, the information is saved in a file at the location (folder and drive) you selected. When you want to work on that file again—to make changes, to print the file, and so on—you open the file.
tip
In addition to the File, Open command, look for shortcuts for opening files. You can click the Open button in the toolbar or use the keyboard shortcut (usually Ctrl+O). Some programs also list the last few files that were opened at the bottom of the File menu. You can click the filename to open that document.