Hi:
The Network latency test (button "Start Latency Test") pings your specific C4C tenant 10 times and measures the latency experienced for every ping and then gives you an average result for the Network latency experienced.
The bandwidth test (button "Download Test") reads fixed size files from your C4C tenant and measures the time taken. Based on the file size, network latency and time taken it calculates the download bandwidth in Mbps.
Again as with any network tests, these are valid for the given time-points. This tool can be used to do a quick check to evaluate any network related issues while access your C4C tenant.
Best regards
Venki