RNA:
Ribonucleic acid (abbreviated as RNA, or Ribonucleic Acid) is a genetic information carrier that exists in biological cells, some viruses and Viroid. RNA is condensed by ribonucleotides through Phosphodiester bond to form long chain molecules. A ribonucleotide molecule consists of phosphoric acid, ribose, and base. There are four bases of RNA, namely, A Adenine, G Guanine, C Cytosine, and U Uracil. U (Uracil) replaces T in DNA.

RRNA:
RRNA, that is, Ribosome RNA, is the largest type of RNA, and also the type of RNA with the largest relative molecular weight among the three types of RNA (tRNA, mRNA, rRNA). It combines with protein to form a Ribosome. Its function is to serve as a scaffold for mRNA, so that mRNA molecules can unfold on it, forming peptide chains (peptide chains are coiled and processed into proteins under the action of the Endoplasmic reticulum and Golgi apparatus matrix, and Prokaryote complete the synthesis in the cytoplasm). RRNA accounts for about 82% of the total RNA. RRNA does not perform its function when it exists alone. It combines with a variety of proteins to form Ribosome, serving as the "assembler" of Protein biosynthesis.