What is the label element used for?

The label element is used for associating a descriptive text to a form field. This provides important context to speech-based web browsers and increase the area on which mobile users can tap to select a specific form field.

We can use it implicitly:

<label>
    <input type="radio" name="crust" value="classicWhite"> Classic White
</label>

Or explicitly (using the for and id attributes):

<label for="classWhite">
    <input type="radio" id="classWhite" name="crust" value="classicWhite"> Classic White
</label>