Ribonucleic acid (RNA) is a polymeric molecule consisting of nucleotides. It can store information similar to DNA, unlike DNA, some RNAs catalize certain chemical reaction. These properties derive from the difference in structure; RNAs are mostly single stranded molecules.
RNA is mostly involved in protein synthesis. The DNA molecules never leave the nucleus but instead use an intermediary to communicate with the rest of the cell. This intermediary is the messenger RNA (mRNA). Other types of RNA—like rRNA, tRNA, and microRNA—are involved in protein synthesis and its regulation.