Article explaining how CD players work

"The data is NOW straightforward" is a mistype. The line should read "the data is NOT straightforward when it is read off the CD"
A further explaination:
The data is coded into those packets before it is put on the CD. (There is another step about the pit length I forgot how it is done, but most of it is here) The information on the CD is not in a straight sequential form. It is cut up, made into packets, error codes added and the packets are scrambled in predefined ways THEN it is put on the CD as little pits. The laser reads the data off the CD and assembles the packets, reads the error codes, rearranges the packets back into correct order, fixes by educated guessing the ones read as errors, then adds the timing and sends this reconstructed stream to the DAC.

There is a great intro to a review that opened my eyes to how CD players work. It doesn't quite answer your question but goes a long way to explain some of it. The article is a review of the PS Audio Perfect Wave in the Dec. '09 issue of 6moons.com by Marja & Henk.
Well worth the read.

Elizabeth..."Educated guessing" is not an error correcting code. The recovered data, that may contain errors, includes redundant data such that the correct original bits are determined. I won't try to explain it. Google "CRC code".

Digital data transmission and storage today almost always involves error correcting coding. It is NOT a band aid for hardware deficiencies that cause errors. By using an error correcting code the transmission bandwidth can be increased to the point where some acceptable frequency of errors, depending on the degree of redundancy, occurs. Although some bandwidth is lost to the redundant data, the overall result is beneficial.

My electrical engineering professor told us this about CD data retrieval. Music CD's came first. There were errors in reading the data, but they were small enough that our ears did not detect the difference. :-) For the data CD's to become useful, error correction algorithms were developed. Your data cannot have any errors in it, especially when you are dealing with data like your bank statement. The data you get off the CD must match perfectly or data is of no use. Most of the differences between CD players are going to be how jitter is handled and how the analog output is done. My professor was one of the researchers who developed the blue laser technology. The pits that mark the data on the surface of the CD are smaller with the blue laser, resulting in greater storage.