Welcome to our first lesson of the JavaScript introductory course! Today, we will uncover the simplicity and power of JavaScript, a universally esteemed programming language renowned for its expressiveness and readability. We'll learn and practice in the CodeSignal environment, where JavaScript and all its components come pre-installed. By the end of this lesson, you'll grasp the foundational aspects of JavaScript and be able to execute your very first JavaScript code. Intriguing, isn't it?

Firstly, we'll focus on the essence of JavaScript and its syntax. Every language, whether it's English, Spanish, or JavaScript, operates under a unique syntax. JavaScript, being a language essential to the web, brings interactivity to websites. Its syntax sets the guidelines akin to the rules of English grammar.

Take, for instance, the following JavaScript syntax showcasing code:

This simple line of code, like a basic English sentence, sends out your first JavaScript message: "Hello, JavaScript Universe!".

In JavaScript, the semicolon (;) acts as a statement terminator, similar to a period in written language. It informs the JavaScript engine that the current statement has concluded, allowing you to start another statement. Here’s a simple analogy for it: just as periods mark the end of sentences in English, semicolons often mark the end of code statements in JavaScript.

Here’s the previous example with an explicit semicolon:

While JavaScript interpreters can often infer where a statement ends even without a semicolon, known as (ASI), it's considered good practice to include them for clarity and to prevent any unforeseen issues, especially in complex scenarios.