Ping is used to find out how quickly a data signal travels from one device to another one in a network. Ping is important for checking the time it takes for a packet of data to be transmitted from your device, go across Internet connections and nodes, then reach another device on the other side, and finally get back to your device.
It measures the the connection or communication between our computer to other computer in the network, and how efficiently it does. When an internet speed test is running, it determines what is called the “connection latency” between the two conveying computers.
Most of the people think that the fast and responsive internet connection is dependent only on the good download speed or upload speed but certainly there is even more to it. Ping also affects the internet connection speed. Generally, ping is referred to the reaction time i.e. time taken to respond towards the request made by the user.
For ping test are used ms units (1000 milliseconds = 1 second). Usual values for optics of cable connection is 5-20ms. Wireless (2.4Ghz, 5Ghz,..) close to 30ms. Mobile connection is much worse >100ms. Ping value affects most gaming over internet and internet telephony (skype).
Credit :
https://gospeedcheck.com/article/what-is-a-good-ping-test-result-65
https://testmyinternetspeed.mystrikingly.com/blog/what-is-ping-speed-test
https://testmyinternetspeed.org/ping-speed-test.html
https://www.meter.net/ping-test/