Firefox comes with the useful option of remembering previously opened windows and tabs when it was closed. So say instead of using a home page that shows up every time Firefox is launched, it is possible to load the regular previously visited websites directly.
This is done by configuring session restore. To do this :
1. Select Edit > Preferences > General in Linux version of Firefox or Tools > Options > General in Windows version.
2. In the Startup section, change the option of” When Firefox starts” from “Show my home page” to “Show my windows and tabs from last time”.
3. Click Close.
From now on, Firefox will automatically load the tabs and windows which were open when it was closed the last time. This is a time saving feature when you regularly keep Firefox open for few select websites, simply enable this option to remember them on close and they will be loaded on the next launch.