Yes, there is in fact a difference. They are actually two different brands owned by two different companies. The two brands are not even affiliated with each other.
The Ralph Lauren Polo brand is an international brand by the American fashion designer with its headquarters in New York. The Polo brand that South Africans know and love is owned by the South African holding company L.A Group LTD.
If you want to tell the difference have a look at the emblems. The Ralph Lauren Polo emblem faces towards the buttons of your shirt; while the South African Polo emblem will face away. In fact these two logos are quite different besides the way that they face. Have a look and compare:
Ralph Lauren Polo logo and South African Polo logo respectively