tRNA = transfer RNA
mRNA = messenger RNA
When you have a gene that encodes a polypeptide (e.g. a protein for hair colour), the RNA polymerase in your cell transcribes this region in a process called transcription. This produce a primary trasncript (an unmodified RNA), which is then spliced (or modified) to become an mRNA. The mRNA then goes out of the nucleus into the cytoplasm and is used as a template for polypeptide synthesis in ribosomes (in a process called translation).
so basically: Gene ---> mRNA ---> polypeptide
tRNA is a special type of RNA that is also produced in a similar manner to mRNA. Except this tRNA is NOT translated. Instead the tRNA goes to the cytoplasm and "helps" the ribosome in translation because it brings amino acid residues that matches to mRNA into the ribosome subunits.
so basically: gene ---> tRNA ---> cytoplasm