What HTML element is used for a form input with multiple lines?

The HTML element used for a form input with multiple lines is <textarea>.

Unlike <input type="text">, which is designed for a single line, <textarea> creates an editable plain-text control that can contain line breaks. Its visible size is commonly set with the rows and cols attributes, although CSS is now preferred for layout and sizing. A typical example is <textarea name="message" rows="5" cols="40"></textarea>.

The element is especially useful for comments, addresses, support requests, biographies, and other responses that may need more than one line. Its initial text is placed between the opening and closing tags, rather than in a value attribute. The browser submits the entered text as part of the form using the control’s name.

A common mix-up is choosing <select>, which presents a list of choices, or <input type="text">, which normally accepts one line. The HTML Standard defines textarea specifically as a multiline plain-text editing control; it does not provide rich-text formatting by itself.