AudaciousArmadillo

Never understood the issue with “closed as duplicate”, it always links to the original question so you get your answer there. And for most things even the duplicate has a solid accepted answer too. Maybe I visit a different part of the site through my questions?

No one: Wikipedia: 🦀

Others mentioned good points but don’t really capture the scale or techniques. A high volume DDoS may even overwhelm the network equipment, so simply saturating the network with garbage traffic. On the smaller scale, a server has limited resources to handle connections. So in the most extreme case, you simple run out of memory to store all the incoming requests. More likely you exhaust a thread pool or run out of connection handles. This “breaks” the server as it may not have resources left to recover to a working state even after the attack has stopped.

As for techniques, DDoS don’t just spam genuine requests. Usually the requests are malformed to have the worst impact on the servers. For example you only send the connection request without completing the full handshake. Now the server has to wait until the connection times out which consumes resources for a potentially long time.

A recent Scott Manly video about radiation in space https://m.youtube.com/watch?v=DJcbevbBzsc.