Genetic mapping is the process of identifying the location of genes on a chromosome and determining the distance between them. It involves the use of molecular markers to track the inheritance of genetic traits across generations.

There are two main types of genetic maps: linkage maps and physical maps. Linkage maps are based on the frequency of recombination between genetic markers, while physical maps are based on the physical distance between markers.

Linkage maps are constructed by analyzing the inheritance patterns of genetic markers in families or populations. The closer two markers are on a chromosome, the less likely they are to be separated by recombination during meiosis, and the higher the frequency of joint inheritance. Linkage maps are useful for identifying genetic loci that are associated with inherited diseases or traits.

Physical maps are based on the actual physical distance between markers on a chromosome. They are constructed by using techniques such as chromosome walking, where overlapping DNA fragments are sequenced and assembled into a contiguous sequence, or fluorescence in situ hybridization (FISH), where fluorescent probes are used to visualize the location of specific DNA sequences on chromosomes. Physical maps provide information about the structure and organization of chromosomes and are useful for identifying large-scale genomic rearrangements, such as deletions, duplications, or translocations.

Overall, genetic mapping is an important tool for understanding the genetic basis of diseases and traits, and for developing new diagnostic and therapeutic approaches based on this knowledge.