Read options while copying a cd. Important!

Hi, I’ve searched a lot in the users guide etc. to find an answer to the questions I have but haven’t had any luck. Please explain in detail.

When copying a cd with Nero burning rom 6, in the “Read Options” tab, what happens if I copy a cd with the “Ignore read errors” options UNCHECKED for both “Data tracks” and “Audio tracks”. and what happens if I copy a cd with them CHECKED. Please explain in detail the difference.

Also what do “Write defect sectors” and “Read sectors in Raw mode” options for “data tracks” do.
Similarly what does “Read indexes of audio data” option for “Audio tracks” do.
Also what is the “Read Media Catalog Number ISRC (slower)” option and the “Use jitter correction” option do.

If I copy a cd using Nero Express, there are no such options, so how is Nero Express supposed to behave while copying a cd in reference to these above options??
Please help. Thankyou

Aint there anybody who can help me ???