點解有d外國人個名後面有Jr?

"The most common name suffixes are senior and junior, limited chiefly to American usage, which may be written with a capital first letter (Sr.) or in lower case (jr.) following the person’s name (with or without an interceding comma). The term 'junior' is only correctly used if a child is given exactly the same name as his or her parent. " Wiki
父子同名同姓, 兒子姓名後面會加上 jr. 用來分別兩人.