Many PTC Sites That I Followed Had Been Atacked By DDOS, what is DDOS Attack?

I have a feeling that is a scam,since most companies can fix a DDOS attack within 3 days tops! For all i know i seen only one company that did that. It was a scam to fool people, that once you reach the payout limit and attempt to withdraw your website changes and says they have been attacked by a DDOS. DDOS attack is when multiple computers enter a single website and overloads it. Though the tricky part is that a DDOS attack is when multiple(millions) of computers are used by 1 persons computer to attack!

Trully i Don't about this much, but as i know if some sites got DDoS attack... they will become Scam Sites ASAP