In a distributed denial-of-service (DDoS) attack, a network of computers work in tandem to overflow an access point and prevent legitamite users from accessing a service.
In a content delivery network (CDN), a set of distributed servers work together to efficiently deliver Internet content, improving loading speed and reliability.
The domain name system (DNS) is often referred to as a phone book for the Internet. It's the worldwide network that connects users to web content via domain names.
The nature of the Internet makes web applications vulnerable to a number of attacks. Web application security involves using a holistic approach to mitigate attacks.