In one sentence: TempData
are like ViewData with one difference: They only contain data between two successive requests, after that they are destroyed. You can use TempData
to pass error messages or something similar.
Although outdated, this article has good description of the TempData
lifecycle.
As Ben Scheirman said here:
TempData is a session-backed temporary storage dictionary that is available for one single request. It’s great to pass messages between controllers.