Arrays are the most basic data structures used in programming. They contain a group of a fixed number of elements that occupy the same space in memory. I.e., the memory occupied is known at compile time. Thus arrays are stored in the stack, and their values can be saved and retrieved very quickly in O(1) time. Languages like Rust which allows enums in Arrays, each element occupies the maximum space which could be required by it.
All arrays consist of contiguous memory locations. We can access the elements with their index. The lowest address corresponds to the first element, and the highest address to the last element.