DDoS

Distributed Denial of Service

Flood traffic attack from many sources to overwhelm a target.

When you'd see it: Security and uptime. A DDoS is one of the most common attacks that takes sites offline.

Why it matters: A DDoS floods a target with traffic from many sources at once to overwhelm it and knock it offline. Defense usually means a service like Cloudflare that can absorb and filter the flood.

Common mistakes: Confusing a DDoS (overwhelm with traffic) with a breach (steal or alter data). A DDoS disrupts availability. It does not, by itself, get the attacker in.