The forward button

Browsers and some operating systems offer an option to move forward and backward through the history of your actions. That means you can return to previous page in a browser or undo a recent action. Similarly, you can move forward again after you used the back button or redo an action.

Browsers

Moving backwards means returning to a page that you have just navigated away from. That means you clicked on some link or typed in another web address and now return to the previous website.
Moving forwards is only applicable after you have navigated backward. For example, you clicked the back arrow once too often. In this case the forward button moves you forward through the pages that you have left. That means, moving forward is undoing your backwards move.

• Chrome and Android
• Chrome and Windows

Operating systems and other programs

Undo an action means reverting the effect of the click or command that you have just done. For example, you accidentally deleted a file or a word from a text document. Undoing this will undelete the file or undelete the word.

Redo an action is only applicable after you have used the undo button. For example, you realise that the file should have gone or the word that you have was really not worthwhile. The redo button will repeat your initial action. That means it is the undo for a previous undo.

• LibreOffice
• Microsoft Word

Why are there two buttons?

It is important to note that neither of these operations is recorded as an event on the timeline. Otherwise you would not be able to use the go backward/undo button more than once in row. The system would undo your going backwards and flicker between the penultimate and latest state. That means you need two buttons to travel through the history of events. Moving backwards always reverts the system to a state in the past. Moving forward re-establishes one of your actions and means going forward to state that you have already been to.