Here's its function:

* Messenger RNA (mRNA): Carries genetic information from DNA in the nucleus to the ribosomes in the cytoplasm, where proteins are made.

* Transfer RNA (tRNA): Transports amino acids to the ribosomes during protein synthesis, matching them to the codons on mRNA.

* Ribosomal RNA (rRNA): Forms the structural and catalytic core of ribosomes, the protein-making machinery of the cell.

In essence, RNA is the intermediary between DNA and protein synthesis, crucial for the expression of genetic information and the production of proteins that carry out essential functions in the cell.