Why do you need NTP (Network Time Protocol)?

I would be interested in what applications the NTP is needed for.

For authentication etc. I know… But what happens if the clocks of the individual network components differ?

Otherwise, I only know that if the time on a laptop, for example, does not match the system time, no connection to the Wi-Fi or LAN is possible. But why is that exactly?

This is used for everything in a network.

that all computers, printers, scanners, etc. Have the same time
for the synchronization of time-critical tasks, e.g. Microsoft Active Directory
for network components such as switches so that events can be better assigned chronologically
etc

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