RNA synthesis is the process by which cells create ribonucleic acid (RNA) from a DNA template. This process begins with an enzyme called RNA polymerase, which binds to a specific region of the DNA known as the promoter. As the enzyme moves along the DNA strand, it unwinds the double helix and assembles nucleotides to form a single strand of RNA, complementary to the DNA template. Once the RNA strand is synthesized, it undergoes several modifications, such as the addition of a 5' cap and a poly-A tail. These modifications help protect the RNA and facilitate its export from the nucleus to the cytoplasm, where it can be translated into proteins.