A deterministic algorithm is a type of algorithm that produces the same output for a given input every time it is executed. This means that if you run the algorithm with the same data, you will always get the same result, making it predictable and reliable. These algorithms follow a specific set of rules or procedures, ensuring consistency in their operations. In contrast to non-deterministic algorithms, which may yield different results on different runs, deterministic algorithms are often used in applications where accuracy and repeatability are crucial. Examples include sorting algorithms like QuickSort and MergeSort, which consistently arrange data in a specific order.