Auto-boxing is the process in JavaScript where a primitive data type is automatically converted to its corresponding object wrapper when you try to access properties or methods that are specific to objects. This process allows primitives to behave like objects temporarily.

Let's take the example of strings and auto-boxing:

const myString = "Hello"; // Primitive string
console.log(myString.length); // Accessing length property
In the above code:

1. myString is a primitive string.

2. When you try to access the length property of myString, JavaScript automatically converts the primitive string to a String object behind the scenes (autoboxing).

3. The length property is then accessed on the temporary String object.

This process allows you to use properties and methods that belong to the corresponding object type (String in this case) on primitive values.

Similarly, auto-boxing occurs for other primitive types like numbers and booleans when you try to use properties or methods associated with their corresponding object wrappers (Number and Boolean, respectively).

const myNumber = 42; // Primitive number
console.log(myNumber.toFixed(2)); // Accessing toFixed method

In this example, myNumber is a primitive number, but when you try to use the toFixed method, JavaScript auto-boxes it to a temporary Number object, allowing you to use the method.

It's important to note that these auto-boxing conversions are temporary, and the original primitive values remain unchanged. Once the property or method is accessed, the temporary object is discarded.