Messenger RNA (or mRNA for short) is a molecule of RNA that serves as a template for translation into protein. A molecule of pre-mRNA is created via transcription from DNA in the nucleus and then is clipped into a final mRNA molecule during RNA splicing.
After the splicing process, the final mRNA molecule exits the nucleus into the surrounding cytoplasm, where it is used as a template for translation into protein (which is then used by the cell for practical purposes) by an assortment of transfer RNA (tRNA) molecules. See the main article on translation for the details of how tRNA traverses the mRNA strand, adding one amino acid at a time to the growing peptide strand according to the genetic code.
