A menu bar is a horizontal strip that contains lists of available menus for a certain program. In Windows programs, the menu bar resides at the top of each open window, while on the Mac, the menu bar is always fixed on the top of the screen. Despite this major difference, the menu bar serves the same purpose on each platform.
Nearly all programs have a menu bar as part of their user interface. It includes menu items and options specific to the particular program. Most menu bars have the the standard File, Edit, and View menus listed first. The File menu includes options such as Save and Open File..., the Edit menu has items such as Undo, Copy, Paste, and Select All, while in the View menu you'll find viewing options such as changing the layout of open windows. Word processing programs, such as Microsoft Word, also include menu options such as Insert, Format, and Font which you will most likely not find in a Web browser's menu bar. But a Web browser may contain menu options such as History and Bookmarks, which you will not find in a word processing program.
Many items located within the menu bar often have keyboard shortcuts that enable you to choose menu options by just pressing a key combination. For example, to copy an object or text selection, most programs allow you to press Control-C (Windows) or Command-C (Mac) instead of selecting Copy from the Edit menu. When browsing through the items in a program's menu bar, you should see the keyboard shortcuts located next to each option that has a shortcut available. The menu bar is a fundamental part of the graphical user interface (GUI), so it is worth you time to get familiar with it. You may even discover features you did not know about before.