| Things You Should Know!! |
| Trojan Horse - is a program that does something that the programmer intended, but the user would not approve of if he knew about it in advance |
| Virus - is a program that spreads, by making copies of itself in one way or another |
| Worm - is a self-sufficient program that spreads by spawning copies of itself on other hosts in a network |
| Flash Crowd - migrates from server to server, leading to hard-to-remedy travelling overloads |