A triplet is when beat is split into three notes, instead of the typical two or four, as shown here:
In modern hip hop, it’s commonplace to find a 16th note pattern for the hi hats, while the open hats are placed in the offbeat. The groove is achieved by the switch-ups from the basic pattern to 32nd or 8th note sections. Triplets are also very effective in hip hop, but we will cover this separately in another section.