hmm.. i'm not really sure anjos cus there are alot of similarities.. but i clearly see the difference in that thai have "roat nam sang" (which is i believe water mix with kamin? in a shell "sang" ), and for laos they dont do that but instead they have "pook kaen" which is a blessing the couple by tieing a white yarn on their wrist..
as for the meaning i'm not quite sure.. but others in here most likely can answer you..
as for the meaning i'm not quite sure.. but others in here most likely can answer you..