What is ctrl + shift + t?

The keyboard shortcut Ctrl+Shift+T is used to reopen the last closed tab in the web browser. This shortcut is supported by most major web browsers including Google Chrome, Mozilla Firefox, Microsoft Edge, and Opera. It is a very useful shortcut for quickly restoring any accidentally closed tabs, or reopening recently closed tabs for reference or further browsing. In addition to web browsers, the Ctrl+Shift+T shortcut is also used in some applications to undo the last closed window or tab.