What are negative indexes and why are they used?

Negative indexes refer to the positions of elements within a list, tuple, or string, counting from the end of the data structure rather than the beginning. For example, in a list with 5 elements, the last element can be accessed using the index -1, the second to last element using the index -2, and so on. Negative indexes can be useful for accessing elements from the end of a data structure without having to know the exact length of the data structure.