Hello! Today, we'll delve into JavaScript's Functions and Scope. These crucial concepts will usher us into an era of organized, efficient, and reusable code. Our goal is to understand JavaScript functions, their declarations, usage, and the concept of scope.

A JavaScript function is a reusable set of instructions, defined using the function keyword. It's invoked, or called, using its name followed by parentheses. For example:

Functions often return a value using the return keyword. The absence of return results in undefined. Here's a function with a return value:

Parameters boost the potency of functions. They're placeholders for data passed when invoking a function. Let's modify our greet function: