The function std::sort is part of the C++ Standard Library, used to arrange elements in a container, such as arrays or vectors, in a specified order. By default, it sorts elements in ascending order, but it can also accept a custom comparison function to sort in different ways. std::sort operates using the "introselect" algorithm, which combines quicksort, heapsort, and insertion sort for efficient performance. It has a time complexity of O(n log n) on average, making it suitable for large datasets. This function is widely used in C++ programming for organizing data effectively.