What is a set of instructions that repeats until a specified condition is met?

A set of instructions that repeats until a specified condition is met is known as a loop. Loops are fundamental control structures in programming that allow developers to execute a sequence of statements multiple times, varying based on certain conditions. The most common types of loops include "for" loops and "while" loops, which continue to iterate as long as their specified condition remains true. This is particularly useful in scenarios where the number of iterations is not predetermined.

In contrast, a function is a reusable block of code designed to perform a specific task but does not inherently repeat itself until a condition is met. An array is a data structure that stores a collection of elements, typically of the same type, and does not involve repetition by itself. A class is a blueprint for creating objects in object-oriented programming and encapsulates data and functionality but does not pertain to iteration directly. Thus, a loop is the correct choice as it specifically describes the repetitive execution of instructions driven by a condition.