The latency – simplified translated as delay – is the time interval by which an event is delayed.
An example of latency in synchronisation: We ask a system for a certain data record. So we make a request to deliver the record with the ID 123456. The requested system needs a certain amount of time to process this request and send the answer. The time interval between sending the request and receiving the response is the latency of a system. The network connection also plays a role here, but it is usually negligible compared to the processing.
Here is an example from our infrastructure: