Subject: does one strand of DNA code for protein and the other strand is redundant ?

Does just one strand of DNA code for a protein and the other strand 
doesn't aid in the coding of that protein but will aid in the coding of 
its own protein, and is this why we have cDNA, which therefore is the code 
of a strand opposite the coding one which has no function in the coding of 
the gene for which the opposite strand will code. however cDNA can become 
the coding DNA when considering the gene the cDNA codes for. or is there 
just one coding strand and another redundant strand.(or do they code 
together) I hope you can answer my question as its causing some confusion 
for me. 
I look forward to your response,
Thanks,
Damien.

Re: does one strand of DNA code for protein and the other strand is redundant ?