DoS is an abbreviation for Denial of Service while DDoS stands for Distributed Denial of Service. Both of these are two different type of attacks used by hackers to interrupt services online. These attacks can be very severe and may cost a company a few million dollars. While both the terms sound similar, there are several differences between the two.

DoS
The basic objective of this attack is to overload the bandwidth and other resources of a particular server.

This attack uses a single computer and a single internet connection to flood the target server with TCP/UDP. Denial of Service attack makes the server inaccessible to others and blocks whatever is hosted on it including the website.

As a DoS is generally sent from a single IP address, it cannot generate a lot of bandwidth and therefore this attack can be easily mitigated. Moreover, if the DoS attacks on Layer 7, it can be easily identified and blocked in your firewall.

A DoS attack does not involve malware and is usually considered a low-level threat which can be stopped easily with the right kind of security.

DDoS
These attacks are worse than DoS attacks as they are launched from several computers. There could be over thousand computers involved in a DDoS attack. The machines are not owned by a single owner, instead they are added by the attacker into the network through malware. This network of machines is known as botnet.

A DDoS attack can be very severe and difficult to tackle as it is tedious to differentiate between the attacker traffic and legitimate traffic. It is considered to be a medium to high-level threat and it does some serious damage to networks and systems as well.

There are several types of DDoS attacks including HTTP or SYN flooding. HTTP flooding involves sending thousands of repeated requests to the server while SYN flooding overfills the TCP network with several packets of data. SYN flooding can be dangerous as this attack can spread to users unrelated to the target.

DDoS attacks are slightly more difficult to guard against. Also, there are several ways to protect your systems from DDoS. One such tactic is to get the ISP discard all the incoming traffic whether legitimate or otherwise, to the web server. This will help protect and secure your client’s personal details.

Why are these attacks carried out?
There could be several reasons for hackers to carry out these attacks. Some corporations may be at war and choose to seek revenge on the web. There have been cases where criminals have extorted money from businesses by attacking their systems.

Most connections, in fact, all the connections are at risk from being attacked by DDoS or DoS. In 2010, giants such as Twitter, EA and the PlayStation Network were attacked by DDoS. These giant companies had to shell out millions to restore their system from the deadly attack.

DDoS attacks occur almost every day and nothing much can be done about it. If you have assets online and are fearful of a DDoS attack, you can contact an expert web security and get a protective software installed. Although this may be turn out to be very expensive, you still need to get the protection. The most important reason why DDoS attacks are widespread than DoS attacks is because it overloads a server to a great extent making it unable to withstand. Also, DDoS employs several computers to attack a particular server which makes the objective easy to achieve. Hence, DDoS attacks are more difficult to handle.

As the old saying goes, prevention is better than cure, it holds true in this case too. The only way to prevent your system from being attacked is to install a high-security antivirus software. This will help keep your computer clean. You can even contact a web-security expert and install an antivirus program which may help protect your computer better.