After testing many STR markers on your Y-Chromosome, you will obtain a bigger picture of your Y-Chromosome and its profile. This is called your "haplotype". Your haplotype is the overall profile for your DNA markers and is unique to different family groups.
By comparing your haploytype to other males with your surname, you will be able to piece together the puzzle of your global family network. Because your haploytpe is passed down to you from your ancient forefathers, all males who share the same lineage as you, even if it is very distant, will have the same haplotype as yourself. Using this powerful information, you can conclusively determine whether a family line with your same surname shares a common ancestor with you (same family line as yourself), and which family groups with your surname originated from a different line.
DNA Marker Test is thus a very powerful means to conduct ancestry research and allows you to confirm existing family lines as well as helping you to discover your global family.