Front USB connections.
There should be 8 cables, 2 red marked V1 or VCC1 and V2 or VCC2, 2 white or yellow marked D1- and D2-, 2 green marked D1+ and D2+ and 2 black marked G1 and G2.
If your motherboard has support for front USB connections you will have a block of 8 or 9 pins marked USB 2.
V1 (red) goes on pin 1, V2 (red) goes on pin 5, D1- goes on pin 2, D2- goes on pin 6. D1+ goes on pin 3, D2+ goes on pin 7. G1 goes on pin 4 and G2 goes on pin 8.
If you have a block of 9 pins, disregard the odd pin as it is not used and the connections are the same as above.
If your motherboard does not have support then obviously you will not be able to use the front USB ports, but you can buy a PCI card with extra USB ports.