Expand/clarify "single pointer" definition

guidelines/terms/21/pointer-input.html

@@ -3,11 +3,10 @@
 
    <p class="change">New</p>
 
-   <p>input device that can target a specific coordinate (or set of coordinates) on a screen,
+   <p>input from a device that can target a specific coordinate (or set of coordinates) on a screen,
       such as a mouse, pen, or touch contact
    </p>
-
-   <p>See also <a href="https://www.w3.org/TR/pointerevents/#dfn-pointer">Pointer Events pointer definition</a> [[!pointerevents]].
-   </p>
+   <p class="note">See the <a href="https://www.w3.org/TR/pointerevents/#dfn-pointer">Pointer Events
+      definition for "pointer"</a> [[!pointerevents]].</p>
 
 </dd>

understanding/21/pointer-gestures.html

@@ -47,6 +47,8 @@ <h2>Intent of this Success Criterion</h2>
 
 			<p>This Success Criterion does not require all functionality to be available through pointing devices, but if it is available to pointer devices then it should not require path-based gestures. While content authors generally need to provide keyboard commands or other non-pointer mechanisms that perform actions equivalent to complex gestures (see Success Criterion 2.1.1 Keyboard), this is not sufficient to conform to this Success Criterion. That is because some users rely entirely on pointing devices, or find simple pointer inputs much easier than alternatives. For example, a user relying on a head-pointer would find clicking a control to be much more convenient than activating an on-screen keyboard to emulate a keyboard shortcut, and a person who has difficulty memorizing a series of keys (or gestures) may find it much easier to simply click on a labeled control. Therefore, if one or more pointer-based mechanisms are supported, then their benefits should be afforded to users through simple, single-point actions alone.</p>
 
+			<p>Single pointer operations include taps and clicks, double-taps and double-clicks, long presses, swiping, dragging, and path-based gestures. Gestures such as "pinch to zoom" or two-finger swipes are <em>multipoint</em> gestures, as they require two or more pointer inputs - in this case, two fingers on a touchscreen.</p>
+
 			<p>An exception is made for functionality that is inherently and necessarily based on complex paths or multipoint gestures. For example, entering your signature may be inherently path-based (although acknowledging something or confirming your identity need not be).</p>
 
 			<p>Gestures that involve dragging in any direction are not in scope for this SC because only the start and end points matter in a dragging operation. However, such gestures do require fine motor control. Authors are encouraged to provide non-dragging methods, for instance, a drag and drop operation could also be achieved by selecting an item (with a tap or keyboard interaction) and then selecting its destination as a second step.</p>