Allele
An allele is a version of a gene. For example, there might be a gene controlling hair color, and one allele produces brown hair while another produces black hair. Often when the news media refer a "gene," they mean an allele. For example, if you read in the paper that scientists have discovered a gene for sarcasm, then that must be the gene's function; it couldn't possibly mean that there is just some gene that everyone has, but one particular version of it seems to be found more often in sarcastic people. Not like anyone would ever try to publish such a thing.