Final answer:
A black-hole attack and a grey-hole attack are two types of attacks that can occur in computer networks. In a black-hole attack, a malicious node in the network selectively drops or discards packets, while in a grey-hole attack, the node selectively drops or modifies some packets. The difference lies in the extent of packet manipulation and the level of disruption caused.
Step-by-step explanation:
A black-hole attack and a grey-hole attack are both types of attacks that can occur in computer networks. In a black-hole attack, a malicious node in the network selectively drops or discards packets, making it appear as if the node is not accessible. This type of attack can disrupt the communication between nodes and cause network congestion. On the other hand, a grey-hole attack is a variation of a black-hole attack where the malicious node selectively drops or modifies some packets, giving the illusion of a normal network behavior. The difference between the two attacks lies in the extent of packet manipulation and the level of disruption caused.