raw events are simply events that come from the server vs a channel or nickname. They can be manipulated in a basic or a complex way; whichever way you choose. Perfect example..... a /whois reply. That reply (among hundreds of others) can be changed VISUALLY via RAW scripting. Some other things you can do are to script:
/names reply
/admin reply
/motd reply
/links reply
/list reply
ban list reply
invites reply
exceptions reply
All of that with RAW scripting. Does that help a bit?