What is a DoS or a DDoS?
A DoS attack prevents anyone to access a certain site or online service (hence the name “Denial of Service”) by flooding the system or the connection with several requests or packets, or similar ways. DDoS (Distributed Denial of Service) is the same but more harmful because the attack starts from many computers usually coordinated by a main computer. Not to be confused with DOS (Disk Operating System) or MS-DOS (MicroSoft-Disk Operating System).