fix(curriculum): adjust callback explanation (freeCodeCamp#64758)

Author: majestic-owl448

curriculum/challenges/english/blocks/lecture-working-with-higher-order-functions-and-callbacks/67329ffd75010f5ddeb4ea13.md

@@ -13,7 +13,7 @@ This concept is fundamental to understanding many aspects of JavaScript, includi
 
 Let's start by understanding what a callback function is in a simple context.
 
-Imagine you have a function that performs a task, and you want to do something after that task is complete. Instead of writing all the code in one big function, you can pass a second function (the callback) to be executed when the first function is done. This allows for more flexible and modular code.
+Imagine you have a function, and within the function you want to do something multiple times. Instead of writing all the code in one big function, you can pass a second function (the callback) to be executed whenever you need that specific something to be done. This allows for more flexible and modular code.
 
 Now, let's introduce the `forEach` method. `forEach` is a built-in method for arrays in JavaScript. It allows you to iterate over each element in an array and perform an operation on each element. The operation you want to perform is defined in a callback function that you provide to `forEach`.
 

curriculum/challenges/english/blocks/review-javascript/6723d3cfdd0717d3f1bf27e3.md

@@ -1352,7 +1352,7 @@ console.log(Math.subtract(5, 3)); // 2
 
 ## Callback Functions and the `forEach` Method
 
-- **Definition**: In JavaScript, a callback function is a function that is passed as an argument to another function and is executed after the main function has finished its execution. 
+- **Definition**: In JavaScript, a callback function is a function that is passed as an argument to another function to be invoked at some point from the first function. 
 - **`forEach()` Method**: This method is used to iterate over each element in an array and perform an operation on each element. The callback function in `forEach` can take up to three arguments: the current element, the index of the current element, and the array that `forEach` was called upon. 
 
 ```js