Network speed is the practical rate at which data moves across a connection, usually measured in bits per second. It is not just the advertised maximum of a plan or link; real speed changes with congestion, signal quality, throttling, device performance, and distance from the network.
In cyber security, speed matters because it affects how quickly attackers can move data and how defenders can detect them. Malware downloads, command-and-control traffic, brute-force attempts, and data exfiltration all depend on available throughput. A slow or unstable link may delay an intrusion, but it can also help hide suspicious activity in normal-looking traffic. Defenders compare observed speeds against normal baselines, watch for unusual bursts or sustained transfers, and use rate limits or traffic shaping to reduce abuse.