Latency is the time it takes for data to travel from one point to another. It is an important factor to consider when measuring the performance of a network or system. There are a number of different ways to check latency, including using a ping command or a specialized latency testing tool.
There are a number of reasons why you might want to check latency. For example, you might want to troubleshoot a slow network connection or you might want to compare the performance of different networks. Checking latency can also be helpful when designing a new network or system.