Arrays are data structures that store collections of items of the same data type, typically in contiguous memory locations. They are characterized by 0-based indexing in many programming languages, meaning the first element is accessed with index 0. Arrays can be created using various methods depending on the programming language. For instance, in some languages, you can use a function like arrayOf() or a constructor like Array() to define an array and populate it with values ¹.

In Luau, a lightweight scripting language, arrays are implemented using tables and can store various data types. The default indexing starts at 1, but custom indices can also be created. Elements can be accessed using the conventional indexing syntax, and if an out-of-range index is used, it returns nil, indicating missing data ³.

In C#, arrays are immutable, meaning their size cannot be changed after creation, and they can hold elements of the same type. They can also be declared as multi-dimensional arrays ⁴. Overall, arrays are versatile and widely used in programming for efficient data storage and retrieval.