Single Nucleotide Polymorphism, often shortened to SNP, pronounced snips, is a DNA sequence which occurs when one nucleotide in the genome differs between species and chromosomes of a human. Almost all single nucleotide polymophisms have two alleles.

One can detect polymorphism by genetic marker using single-nucleotide polymorphism which is able to even tell mutation of a gene.

The dbSNP is a database archive of genetic materials records which may be accessed freely. It holds genetic information across species. "dbSNP" stands for the Single Nucleotide Polymorphism Database.

Single nucleotide polymorphisms:SNP is a DNA sequence variation occurring when a single nucleotide - A, T, C or G - in the genome.