There are two main types of genome mapping: genetic mapping and physical mapping. These approaches help create maps of genomes for identification and determining the relative position of genes or loci in an organism.

Genetic mapping is created by carrying out crossover analysis. It gives an estimate of distances between two or more genetic loci responsible for a set of well-known phenotypes. The rate of crossing over (recombination frequency) between genes or loci is used to measure relative genetic distance. Genetic distances are measured in centimorgan or map unit, where one map unit equals one percent of observed recombination.

Physical mapping is based on map features such as restriction enzyme sites (restriction mapping) and sequence tagged sites (STS). In restriction mapping, restriction enzymes cut DNA at specific base sequences, resulting in DNA fragments that can be visualized by agarose gel electrophoresis, where fragments are separated based on their sizes.

In comparison, genetic mapping estimates genetic distances based on recombination frequencies and phenotypic observations, while physical mapping relies on actual physical features of the DNA molecule. Both approaches are crucial for comprehensive genome research and understanding the organization of genetic material.