I think roger mean 'I understand and I will do exactly what you want me to do'? copy just means you heard and understand. "Do you copy?" means Are you hearing me properly? over means you are done speaking and the other person can start speaking . over and out means you are done speaking and are ready to stop transmitting, so you wait for the other person to finish and when he also says "over and out" you can turn your radio off.

Yes, that's it! "Wilco" I totally forgot that!! "will comply" it's not too hard to remember. I am stupid~~ LOL

Keep in mind that roger and copy is only used for military settings. For police, they have codes they use and do not use the same terminology. "Do you copy" does not mean "are you hearing me properly." In the military you would use "radio check" to check the signal. "Copy" means you understand what was said. Roger means you understand and will carry it out. You can also say Wilco, which is short for "will comply." However, you never say "Roger wilco" like in the movies. That's fake. You use one or the other. You can also say "Lima Charlie" which is short for "loud and clear" meaning you understand and will carry it out. Again with military, "affirmative" is yes and "negative" is no. There is also an phoenetic alphabet that is used to sound out individual letters. Alpha, Bravo, Charlie, and on down. Keep in mind this is for the military. The police use different indicators that are simpler.