With the Open menu you can open favorite and recent applications, applications located in the Applications or Utilities folders, and System Preferences panes. In addition to that, the Open menu lets you run AppleScripts.
Click the blue button in the menu panel or menu bar or, if you have enabled it, press the Open menu keyboard shortcut.
Use the menu panel to display menus
Show Application Wizard in the menu bar
Use keyboard shortcuts to display menus
To open an application or run an AppleScript, choose it from the Open menu.
To force a 64-bit and 32-bit capable application to open in 32-bit mode, select it in the Open menu and press the Control key.
To open an application without restoring its windows, hold down the Command and Option keys and choose it from the Open menu.
Open menu items are described below. To add or remove items from the Open menu, open the Application Wizard pane in System Preferences and click Menus. Click the Customize Menus button and click Open.