In JavaScript a loop is a programming construct that allows a section of code to be executed repeatedly until a certain condition is met. There are several types of loops in JavaScript: 1. for loop: It repeats a block of code a specific number of times. It consists of three parts: initialization condition and iteration statement. Example: for (let i = 0; i 2. while loop: It repeats a block of code as long as a specified condition evaluates to true. Example: let i = 0; while (i 3. do-while loop: It is similar to the while loop but the code block is executed first before checking the condition. Example: let i = 0; do { console.log(i); i++; } while (i 4. forEach loop: It is a method available for arrays to execute a provided function once for each element in the array. Example: const numbers = [1 2 3 4 5]; numbers.forEach(function(number) { console.log(number); }); These loops are used to automate repetitive tasks or iterate over arrays and objects to perform operations on their elements.