A distributed denial-of-service (DDoS) attack aims to exhaust the resources of a network, application or service so that genuine users cannot gain access. A DDoS assault is launched simultaneously from multiple different hosts and can affect the availability of even the largest enterprises internet services and resources. In 2014 there were 159 attacks over 100 Gbps, the largest being 400 Gbps. DDoS attacks are a daily occurrence for many organizations; based on the thenth Worldwide Infrastructure Security Report, 42% of respondents saw more than 21 DDoS.”]
Source: https://gbhackers.com/ddos-attack-prevention-method-enterprises-systems-detailed-report/