What is a DDOS ?

[wraggster]

I noticed that pdroms has been down a few days then when i left it for 5 mins to load it said it had been DDOS'ed, what actually is a DDOS, i presume its denial of service but how does it work

[BlueCrab]

DDoS is a Distributed Denial of Service. Generally, what happens in one of them is a bunch of clients (such as a botnet) throws many many more requests at a server than it can handle. These may be valid requests (such as normal HTTP requests for pages), or invalid ones that are specially crafted to break certain software running on the server (exploit vulnerabilities, etc).

Basically, it involves overloading a server so that it can't keep up with the valid "good" requests from normal traffic.