Want Safari to remember which web pages you had open so they will all appear when you restart the browser? If you do not have Private Browsing enabled, and you do not empty your Cache and History, you can easily recall all of your previously opened windows.
When browsing with several web page windows open, and/or tabs open, choose to quit Safari by right-clicking on the icon in the Dock or typing the shortcut
Command + Q.
Now, restart Safari. Go to the History menu, and choose Reopen All Windows From Last Session.