Break pads

ive just taken delivery of front and rear break pads for my pulse lightspeed 125...0ne set pads has a groove through the middle and one set has three grooves..is there any reason for this has I'd have thought both sets would be the same...I've now got to determine which set is for the front and which set is for the back

 

Apparently it aids cooling of the pads and increases brake efficiency a little. Don't ask me how.

 

Does it matter which set goes to the front or rear has both sets are same shape,length and diameter

 

if they the same shape and size ie all four are exactly the same, then it does not matter what set of two goes in the front or rear.

 

Apparently the pads with the three grooves go in the rear,not sure why but I'll put them in the rear