To determine the relationship between two people they must have a "common ancestor." After finding the common ancestor, determine how both people are related to the common ancestor (i.e, one person is a grandson and the other is a g-granddaughter.) This would make the two individuals with the common ancestor..."first cousins 1 time removed."
Here is an actual example: My son and Robert "Bren" Manning's common ancestor is John Manning, born 1838. My son is a "3rd great grandson," and Robert is a "great grandson." This would make my son and Robert 2nd cousins 2x removed.
