I hope i would get logical answers. I request to post it as soon as possible.
DNA is a polynucleotide. The above structure is of a nucleotide which has three components, a nitrogenous base(yellow), a pentose sugar(purple) and a phosphate group. These nucleotides form phosphodiester linkages to form a polynucleotide.
These phosphodiester linkages are formed between 3' and 5' carbons of the pentose sugar which is shown in the above image.
The end of DNA having a free phosphate group at 5' of pentose sugar is known as the 5'-end of DNA, and the end of DNA having a free hydroxyl group at 3' of pentose sugar is called the 3'-end of DNA.
Here, you can play with the DNA.