An [[attack]] that makes some or all of the network unusable, thereby affecting [[availability]]. Typically such attacks flood parts of the network with traffic, or render components unusable That means a billion requests to a component, or smashing it with a hammer, and technically are both denial of service attacks We might try to overload the compute, by passing requests that are very computationally expensive. Alternatively, we could overload the network with packets. There is a specific subset of DoS attacks that are distributed across multiple attacking hosts: these are called [[Distributed Denial of Service|DDoS]] attacks