An array, also known as a vector, is one of the simplest data structures in computer programming. Arrays hold a group of equally sized data elements in a continuous block of memory. Individual elements are accessed by index using integers (contrast: associative array).
Arrays permit efficient (constant time, O(1)) random access but not efficient insertion and deletion of elements (which are O(n), where n is the size of the array). Compare linked lists which have the opposite trade-off.
Most programming languages have arrays built in.