Many times it happens that we accidentally close a browser window or tab and wanted to reopen it if we could. Gtricks (Google Tricks) has posted an article on this, I just expanded it.
Reopen Recently Closed Tab / Window in Firefox
To reopen the last closed Firefox tab, use the keyboard shortcut Ctrl+Shift+T (Ctrl+T is for opening a new tab).
List of Recently Closed Tabs is available on the Firefox menu itself. Go to History > Recently Closed Tabs.
Hold down Ctrl+Shift and press T repeatedly to open the previously closed tabs, upto the last 10 tabs.
List of Recently Closed Firefox windows is available on the Firefox menu itself at History > Recently Closed Windows. You can as well press Ctrl+H for viewing the history of closed tabs /windows in the sidebar. Ctrl+SHift+H opens the history details in a separate library window.
To reopen the recently closed Firefox window, press the keyboard shortcut Ctrl+Shift+N (Ctrl+N is for opening a new window)
Reopen Recently closed Tabs / Windows in Google Chrome
Whenever you open a new tab or window in Google Chrome browser, it displays the list of recently closed tabs and windows to the right side of the new tab. recently closed tabs are listed with their title, and recently closed chrome windows are listed with favourite icons of the tabs those were open in the window, within brackets.
To reopen the last closed tab, use the keyboard shortcut Ctrl+Shift+T (Ctrl+T is for opening a new tab).
To reopen the recently closed Chrome window, press the keyboard shortcut Ctrl+Shift+N (Ctrl+N is for opening a new window)
You can find all the closed tabs and windows and other related information in the History: go to Tools > History or use the keyboard shortcut Ctrl+H or type in chrome://history/ at address bar.