What is the difference between DNA and RNA?

DNA is a double helix, made up of two polynucleotide strands.  RNA is comprised of only one polynucleotide strand.  

The sugar in the sugar-phosphate backbone of DNA is deoxyribose, whereas ribose is present in RNA.  

Both DNA and RNA contain the bases adenine, guanine and cytosine.  In DNA, adenine pairs with thymine, but in RNA it pairs with uracil.  

DNA is more stable than RNA.