What is the term used to describe the arrangement of objects where the order matters?

The term that describes the arrangement of objects where the order matters is "permutation." In permutations, the sequence in which the objects are arranged directly influences the outcome. For example, if you have a set of three letters A, B, and C, the different arrangements such as ABC, ACB, BAC, BCA, CAB, and CBA are considered distinct permutations. This contrasts with combinations, where the order does not matter, meaning the arrangement ABC would be considered the same as ACB or BCA.

Therefore, permutations are crucial when the focus is on sequences or arrangements where the order is significant, such as in problems involving rankings, arrangements, or specific sequences of items.