Let's explore JavaScript variables — the essential containers for storing data — along with assignment and equality operators, which facilitate our interaction with these variables. After this lesson, you'll understand how to define, use variables, and comprehend the operators.

Think of a variable in JavaScript as a box. This box stores data that can be changed, accessed, and manipulated within a program. Variables are declared in two ways: let and const, each with its own characteristics:

In JavaScript, we frequently encounter situations in which a variable doesn't have a value. In such cases, the null and undefined types come into play.

Imagine you possess a flower jar (variable), but it's empty. There is no flower inside. This absence of content is what null in JavaScript represents — an intentionally empty or non-existent value.

Suppose you have a label for a candy jar, but you don't actually have the jar. This is where undefined comes in. It indicates that a variable has been declared, but doesn't yet hold any value.

Here's a code example to illustrate: