What is a Denial-of-Service (DOS) Attack?

Denial-of-Service Attack (DoS attack) is a form of cyber-attack in which the hacker attempts to make a computer or network resource unavailable by temporarily or indefinitely disrupting services connected to the Internet. Denial of service is often accomplished by overloading the targeted computer or website with requests. This can effectively render the target system inaccessible to legitimate users, disrupting its normal operation.