Not really sure what you are referring to here, details would be appreciated. Taking a stab, here is information on Denial-of-Service threats.
Never heard of a delay threat, but a denial of service attack is an attempt to overload a service so that it becomes in accessible to other users. There are several ways of doing this, but basically you flood a website with so many requests that it can’t reply to legitimate requests.
Same here, never heard of it before, but according to this article, here is the definition of a Delay Threat:
“<b>Delay</b>: a temporary inhibition of a service, is a form of usurpation, although it can play a supporting role in deception. Typically, delivery of a message or service requires some time t; if an attacker can force the delivery to take more than time t, the attacker has successfully delayed delivery. This requires manipulation of system control structures, such as network components or server components, and hence is a form of usurpation. If an entity is waiting for an authorization message that is delayed, it may query a secondary server for the authorization. Even though the attacker may be unable to masquerade as the primary server, she might be able to masquerade as that secondary server and supply incorrect information. Availability mechanisms can thwart this threat.”