TERM:
Denial of service attack (DoS)

Definition:

An attack on a computer system or network that causes a loss of service to users. A network of computers is used to bombard and overwhelm another network of computers with the intention of causing the server to ‘crash’. A Distributed Denial of Service (DDoS) attack relies on brute force by using attacks from multiple computers. These attacks can be used to extort money from the businesses targeted.