1. A nitrogenous base: This is a molecule containing nitrogen that can be either a purine (adenine or guanine) or a pyrimidine (cytosine, thymine, or uracil).

2. A five-carbon sugar: This is a pentose sugar, either ribose or deoxyribose.

3. A phosphate group: This is a negatively charged group consisting of a phosphorus atom bonded to four oxygen atoms.

These three components are linked together in a specific order to form a nucleotide.