Spectral Karyotyping (SKY) is one of the most useful cytogenetic techniques for detecting the whole genome in all types of chromosomal abnormalities in any individual. This is because all types of chromosomal abnormalities affect many genes, leading to cancers and many types of syndromes such as Edward's and Down's syndromes, which result in mental disabilities, malformations, and/or improperly developed body parts in affected individuals. This review will explain how Spectral karyotyping works and how it is performed. In addition, the classification of chromosomal abnormalities is explained.