What is a distributed denial of service (DDoS) attack?

It is difficult for a single site to generate enough traffic to launch an effective denial of service (DoS) attack. Large spikes in traffic are also easy for sites to detect and defend against. So instead of using a single attacking node, denial of service attacks are often launched by a bunch of computers acting together. This is referred to as a distributed denial of service (DDoS) attack. Because attackers do not usually have legitimate access to a sufficient number of machines to launch a DDoS, frequently groups of hacked machines referred to as botnets are used.

Credits: Talking: Geoffrey Challen (Assistant Professor, Computer Science and Engineering, University at Buffalo). Producing: Greg Bunyea (Undergraduate, Computer Science and Engineering, University at Buffalo).

[prabodamadushan]

Really helpful and understanding video. Thanks !