yea use next time search... just im bored so ill answer this time i hope it will help
1. server comunicates with your client using packets.. and with editing this packets u can override some function tho not all some stuff like amount of your money is stored on server side and u cant edit it... so when u send packet to drop 99999 money it will check if u have enough and then it will let u or not...SV or QOProxy are based on these packets.. so u can work on your computer without having your CO window as main... pixel based bots wont allow u this
2. itemtype.dat is file where are stored names and links to pics of equipments etc when u download a1blaster's edited files u can see on floor weapon quality but not +1s... so its good when u r just running somewhere and kill some mob and it does drop super so u can see that its worth to go back
3. item decrypter is tool which u would need if u want to edit this file which i mentioned above... i think u wont need it... thanks to a1blaster

he is very fast with this after every patch when u would need new one ull find in his topic new files for download its pinned also so if u use search u can find it easy...