What is the difference between the 5 prime and 3 prime ends of a nucleic acid strand?

The 5' end of a nucleic acid strand refers to the end where the phosphate group is attached to the 5th carbon of the sugar molecule, while the 3' end refers to the end where the hydroxyl group is attached to the 3rd carbon of the sugar molecule. This distinction is important for understanding the directionality of nucleic acid synthesis and the reading of genetic information.