In JavaScript, data comes in various types, such as numbers, strings, booleans, arrays, and objects.Let's break it down. First up, we have numbers. They can be integers or floating-point numbers. Here's how you declare a number variable: let number = 10;Next, we have strings, which are sequences of characters enclosed in quotes. Here's an example: let string = 'Hello, world!';.Booleans represent true or false values. You declare a boolean variable like this: let boolean = true;.Arrays are used to store multiple values in a single variable. Here's how you create an array: let fruits = ['apple', 'banana', 'orange'];.Lastly, objects allow you to store key-value pairs. Here's an example of an object: let person = { name: 'John', age: 30 };.