A gene is a series of codons along part of a DNA molecule that, together, will code for a protein. One gene actually can code for more than one protein. It depends on how you read the code in the DNA, how you mature the mRNA(s) (splicing) and how you translate and modify the resulting protein(s).
It can take thousands of codons, or more, to make a single gene for a single protein. ONE gene for ONE protein, composed of MANY codons, or nucleotide base combinations.