What is the main difference between a DOS attack and a DDOS attack?

The main difference between a DOS (Denial of Service) attack and a DDOS (Distributed Denial of Service) attack lies in the number of hosts involved in the attack. A DOS attack typically originates from a single source or host, meaning that it relies on one system to flood a target with excessive requests to overwhelm it and disrupt its normal operation. In contrast, a DDOS attack employs multiple compromised host systems to launch the attack, leveraging the power of many sources simultaneously to amplify the impact on the target. This distributed approach often makes it much more difficult for the target to mitigate the attack, as it comes from numerous locations rather than a single entity. This fundamental difference in the scale and coordination of the attacking systems distinguishes DOS from DDOS attacks.