The difference between DNA and RNA in the most basic way is that DNA is double stranded whereas RNA is single stranded. The next difference is that DNA is made from deoxyribose and RNA is made from ribose. Ribose has a hydroxyl group attached to it, making it less stable. The third difference is in the complementary nucleotides that DNA and RNA encode for. DNA has thymine (T), guanine (G), adenine (A) and cytosine (C). G is always paired with C and A is always paired with T in DNA. In RNA, there is no thymine, so adenine is transcribed uracil (U). DNA is contained within the nucleus of a cell and cannot leave. The job of RNA is to copy a strand of DNA in the nucleus to carry out the manufacture of a specific protein, carry the code outside into the cytoplasm of the cell, where it attaches to a ribosome that manufactures protein strands to become amino acids. Each strand of RNA can carry the recipe for several protein strands.
Here is how a protein is made. First, messenger RNA (mRNA) is manufactured in the nucleus of the cell and copies the recipe for a specific protein. The mRNA brings the recipe outside the nucleus to the ribosome; the site of protein synthesis inside the cell. Ribosomal RNA (rRNA) with the help of transfer RNA synthesizes a single amino acid.