The Resume feature lets you re-open apps in the same state you left them. For example, when you quit Safari, any webpages you're viewing are fully restored the next time you open Safari. If you have Pages documents open when you log out of your user account, those documents open again the next time you open Pages.
With Resume, you don't have to worry about saving your work or finding the files you were previously working with. It all happens automatically. If you don't want some or all of your documents and windows to automatically re-open, you can use the features of Resume to control how it works.
When you log out and log in
When you log in, apps that were open the last time you used your Mac automatically re-open. When you log out, you can select or deselect "Reopen windows when logging back in" from the Log Out window. This option sets whether your apps should re-open the next time you log in. It remains selected the way you last set it, so you have to change this setting only when you want to change the current behavior.
To temporarily prevent apps from opening when you log in, hold the Shift key during login. This prevents apps from opening automatically, even if you selected the option to open them the last time you logged out.
When you open and quit an app
When you open an app, it automatically re-opens the windows you were working with the last time you quit the app. If you don't want apps to automatically re-open documents and windows, select "Close windows when quitting an application" (OS X Mountain Lion v10.8 or later) or deselect "Restore windows when quitting and re-opening apps" (OS X Lion v10.6) from the General pane of System Preferences.
If an app continues to re-open its documents and windows when this feature is turned off, check the app's preferences for a similar feature. Some apps have their own setting for restoring windows.
To temporarily prevent an app from re-opening its documents and windows, hold the Shift key while you open the app.
Use Login Items
If you want an app to open every time you log into your user account, you can add it to the Login Items pane of System Preferences. Login Items always open, no matter which Resume settings you've set.
- From the Apple menu (), choose System Preferences, then click Users & Groups.
- Select your user account from the list of users.
- Click Login Items.
- Drag an app or document into the Login Items list, or click and select an item.
When you're done adding Login Items, close the Users & Groups window.
To temporarily prevent a login item from opening, hold the Shift key while logging in. This tells your Mac to skip login items, and any apps and windows that were open when you logged out won't automatically re-open during this login.