mRNA is polycistronic in prokaryotes which means that multiple genes are present on a single transcript and the single promoter initiates transcription of all those genes and regulates their expression. They have multiple initiation and termination codons and thus translate more than one protein.
mRNA is monocistronic in eukaryotes that contains the coding region of only a single gene and thus carry single initiation and termination codons thereby coding for a single polypeptide.