Square waves or 1's and 0's?

digital signal not only has ones and zeroes, but rather characterised by sampling frequency and sampled amplitude as mentioned before voltage level.
an arbitrary point of signal could be captured knowing the particular voltage and the value of the signal 0(low) or 1(high). The low could be let's say 0V and high could be +50mV etc...

0-s and 1-s are only rererence values of digital signal, but not the actual physical ones for those who thinks that 0s and 1s are 'traveling' accross the digital cable.
electrones are the only ones capable of doin' that

Almarg - with S/PDIF the transport level is still 1's and 0's, but the protocol of the interface requires encoding the data to limit the number of consecutive 1's or zeroes, allowing a clock to be recovered as well as the data.

Steve N.
Empirical Audio

I guess we all interpreted your question a little different.

My question was oversimplified and came out of ignorance. Your anwsers will give me all the reading I want tonight because I have to re-read. You guys are over my head but it's fun trying to understand it. You are a great source, better than anything else I've found on the net.

I was tired of reading the argument that the quality of cable doesn't matter because the signal is simply ones and zeros. I have two digital coax cables and it clearly does matter.

Thank you.

Lynne

that was a true statement Lynne simply because digital cable carries simple shape signal compared to an analogue music.