A Single Nucleotide Polymorphism, or SNP, is a variation in a single nucleotide that occurs at a specific position in the genome. These small changes can happen in the DNA sequence and may affect how genes function, potentially influencing traits such as physical characteristics or susceptibility to diseases. SNPs are the most common type of genetic variation among people. They can be found in both coding regions, which determine protein structure, and non-coding regions, which may regulate gene expression. Researchers study SNPs to understand genetic diversity and their role in health and disease.