I noticed that when starting Windows and being prompted for a password, if you enter the right password it logs in right away, but if the entered credentials are wrong, you have to wait several seconds for a negative response.
This way I can tell if I mistyped long before the system gives me an answer, just by the amount of time I have to wait.
What's the reason for this behaviour?
My best guess would be that the system makes additional checks for the account data on different locations (network?) if no matching login data was found.