The document outlines various HTML form elements including <input>, <label>, <select>, <textarea>, <button>, <fieldset>, <legend>, <datalist>, <output>, <option>, and <optgroup>. It explains the functionality and use cases for each element, such as the <input> element's versatility depending on the type attribute, and the importance of <label> for accessibility. Additionally, it discusses grouping data with <fieldset> and defining options with <select> and <datalist>, among other features.