Dual-pivot is a sorting technique used in computer science, particularly in algorithms like QuickSort. It improves efficiency by using two pivot elements instead of one. This allows the algorithm to partition the data into three sections: values less than the first pivot, values between the two pivots, and values greater than the second pivot. By utilizing two pivots, dual-pivot can reduce the number of comparisons needed during the sorting process. This often leads to faster performance, especially with large datasets, making it a popular choice for modern sorting implementations in programming languages like Java and Python.