Javascript variables are containers for storing data.

JavaScript Variables can be declared in 4 ways:

• Using const
• Using let
• Using var
• Automatically

JavaScript Identifiers

All JavaScript variables must be identified with unique names.

These unique names are called identifiers.

Identifiers can be short names (like x and y) or more descriptive names (age, sum, totalVolume).

The general rules for constructing names for variables (unique identifiers) are:

• Names can contain letters, digits, underscores, and dollar signs.
• Names must begin with a letter.
• Names can also begin with $ and _ (but we will not use it in this tutorial).
• Names are case sensitive (y and Y are different variables).
• Reserved words (like JavaScript keywords) cannot be used as names.

JavaScript identifiers are case-sensitive.