Video narration
Why write the same instructions again and again? Think of a sandwich recipe: ingredients go in, steps happen, and a sandwich comes out. Next time, you reuse the recipe instead of rewriting every step. In C, a function is a named set of instructions for one task. You define it once. It waits-writing it does not run it. The program runs it when you call it by name. Here's a tiny example: add has two parameters, or input slots. It receives two numbers, adds them, and can return the answer; returning a value is optional. Calling add(2, 3) gives 5. Call add again with different numbers, without rewriting its instructions. Like your sandwich recipe, the same function works with new ingredients. So why repeat the steps? Write them once, then call the function whenever you need the result. This keeps your C program clear and reusable.