File integrity: State of a computer (electronic) file in which no alteration, addition, or deletion has been made, and which is exactly the way it was stored by its originator. http://www.businessdictionary.com/definition/file-integrity.html I would like to ask what "file integrity" is because the definition makes no sense to me. What does it mean by "no alteration, no addition" ? I can create a .txt file I can add something to it and I can alter the file but what does "file integrity" express for this situation ? Thank you.