DoS vs DDoS

The Difference between DDoS and #DoS

#DoS
A DoS Attack is a Denial of Service attack.
This means that one computer and one internet connection is used to flood a server with packets (TCP / UDP). The point of such a denial of service attack is to overload the targeted server’s bandwidth and other resources. This will make the server inaccessible to others and blocking the website or whatever else is hosted there.

#DDoS
A DDoS Attack is a Distributed Denial of Service Attack.In most respects it is similar to a DoS attack but the results are much different. Instead of one computer and one internet connection the DDoS attack utilises many computers and many connections. The computers behind such an attack are often distributed around the whole world and will be part of what is known as a botnet. The main difference between a DDoS attack vs a DoS attack, therefore, is that the target server will be overload by hundreds or even thousands of requests in the case of the former as opposed to just one attacker in the case of the latter.
Therefore it is much, much harder for a server to withstand a DDoS attack as opposed to the simpler DoS incursion

Types of #DDoS Attacks

DDoS - Denial of Service

Volume Based Attacks - This type of attack includes UDP floods, ICMP floods, and other spoofed packet floods. The goal of this DDoS attack is to saturate the bandwidth of the attacked site. The magnitude of a volume-based attack is usually measured in Bits per second.
Protocol Attacks - This type of DDoS attack consumes the resources of either the servers themselves, or of intermediate communication equipment, such as routers, load balancers and even some firewalls. Some examples of protocol attacks include SYN floods, fragmented packet attacks, Ping of Death, Smurf DDoS and more. Protocol attacks are usually measured in Packets per second.

Application Layer Attacks -
Perhaps the most dangerous type of DDoS attack, application layer attacks are comprised of seemingly legitimate and innocent requests. The intent of these attacks is to crash the web server. SDome examples of application layer attacks include Slowloris, Zero-day DDoS attacks, DDoS attacks that target Apache, Windows or OpenBSD vulnerabilities and more. The magnitude of this type of attack is measured in Requests per second.