I remember watching a video (or an elearning) created by someone some 10 years ago that explained how TCP/IP works. It explained how an email, IM, HTTP works so easily. All of us watching it simply stood up and clapped at the end. We were all into training then! 😉 Unfortunately, couldn’t find the video on the net, maybe there are newer versions available now.
Here is an explanation of how a large DDoS attack is generated (or orchestrated!) in simple words.