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

The 3' end of a nucleotide strand refers to the end where the sugar molecule has a free hydroxyl group attached to the 3rd carbon atom, while the 5' end refers to the end where the sugar molecule has a phosphate group attached to the 5th carbon atom. This structural difference affects how nucleotides are added during DNA replication and transcription.