Biological databases emerged as a response to the huge data generated by low-cost DNA sequencing technologies. One of the first databases to emerge was GenBank, which is a collection of all available protein and DNA sequences. Maintained by the National Institute of Health (NIH) and the National Center for Biotechnology Information (NCBI), GenBank paved the way for the Human Genome Project (HGP). The HGP allowed the complete sequencing of genetic blueprint. The data stored in biological databases is organized for optimal analysis and consists of two types: raw and curated (or annotated). Biological databases are complex, heterogeneous, dynamic, and yet inconsistent. The inconsistency is due to the lack of standards at the ontological level.