Editorial: Provide examples of types of menus (#2056)

Co-authored-by: Valerie Young <[email protected]>
Co-authored-by: James Craig <[email protected]>

index.html

@@ -5036,7 +5036,8 @@ <h4>Plain HTML or Polyfill DOM Result of the MathML Quadratic Formula</h4>
 			<rdef>menu</rdef>
 			<div class="role-description">
 				<p>A type of <a>widget</a> that offers a list of choices to the user.</p>
-				<p>A menu is often a list of common actions or functions that the user can invoke. The <code>menu</code> <a>role</a> is appropriate when a list of menu items is presented in a manner similar to a menu on a desktop application.</p>
+				<p>A menu is a container, generally rendered as a popup or overlay, for a set of menu items that can be invoked to perform an action or function. The function is almost always closely related or directly related to the element that the user activated to invoke the menu. Activating a menu item both performs the associated function of the menu item, and results in the automatic dismissal of the menu.</p>
+				<p>The <code>menu</code> <a>role</a> is appropriate when a set of menu items is presented in a manner similar to a popup menu. For instance, a menu could be used to represent a context menu for its invoking element, or it would be used to render sub-menus for items of a <rref>menubar</rref> or another <code>menu</code> popup.</p>
 				<p>To be <a>keyboard accessible</a>, authors SHOULD manage focus of descendants for all instances of this <a>role</a>, as described in <a href="#managingfocus">Managing Focus</a>.</p>
 				<p>Elements with the role <code>menu</code> have an implicit <pref>aria-orientation</pref> value of <code>vertical</code>.</p>
 			</div>