diff --git a/examples/symbol-atlas-webgl.html b/examples/symbol-atlas-webgl.html
index 36774b6681..666bc43ab5 100644
--- a/examples/symbol-atlas-webgl.html
+++ b/examples/symbol-atlas-webgl.html
@@ -34,6 +34,12 @@
           <h4 id="title">Symbols with WebGL example</h4>
           <p id="shortdesc">Using symbols in an atlas with WebGL.</p>
           <div id="docs">
+            <p>When using symbol styles with WebGL, OpenLayers would render the symbol
+            on a temporary image and would create a WebGL texture for each image. For a
+            better performance, it is recommended to use atlas images (similar to
+            image sprites with CSS), so that the number of textures is reduced. OpenLayers
+            provides an <code>AtlasManager</code>, which when passed to the constructor
+            of a symbol style, will create atlases for the symbols.</p>
             <p>See the <a href="symbol-atlas-webgl.js" target="_blank">symbol-atlas-webgl.js source</a> to see how this is done.</p>
           </div>
           <div id="tags">webgl, symbol, atlas, vector, point</div>
diff --git a/src/ol/style/atlasmanager.js b/src/ol/style/atlasmanager.js
index f53ccb3c24..990a98d622 100644
--- a/src/ol/style/atlasmanager.js
+++ b/src/ol/style/atlasmanager.js
@@ -30,8 +30,8 @@ ol.style.AtlasManagerInfo;
  * atlas. After that, when new atlases are created, they will have
  * twice the size as the latest atlas (until `maxSize` is reached).
  *
- * If an application uses a lot, or a lot of large images, it is recommended to
- * set a higher `size` value to avoid the creation of too many atlases.
+ * If an application uses many images or very large images, it is recommended
+ * to set a higher `size` value to avoid the creation of too many atlases.
  *
  * @constructor
  * @struct