What is the purpose of styles() method in jquery ?

What is the purpose of styles() method in jquery ?

i was just going through the source of jquery css() method and came across the following lines of code : 

  1. function (name, value) {
  2.     return access(this, function (elem, name, value) {
  3.         var styles, len, map = {},
  4.             i = 0;

  6.         if (jQuery.isArray(name)) {
  7.             styles = getStyles(elem);
  8.             len = name.length;

  10.             for (; i < len; i++) {
  11.                 map[name[i]] = jQuery.css(elem, name[i], false, styles);
  12.             }

  14.             return map;
  15.         }

  17.         return value !== undefined ? jQuery.style(elem, name, value) : jQuery.css(elem, name);
  18.     },
  19.     name, value, arguments.length > 1);
  20. }
now inside his code there is a method  style()  which is being used, now when i googled i did't find any documentation about this perticular method , can somebody tell me of what use or for what purpose does this method exists in jquery ? , in the source i see the following code :

  1. function (elem, name, value, extra) {
  2.     // Don't set styles on text and comment nodes
  3.     if (!elem || elem.nodeType === 3 || elem.nodeType === 8 || !elem.style) {
  4.         return;
  5.     }

  7.     // Make sure that we're working with the right name
  8.     var ret, type, hooks, origName = jQuery.camelCase(name),
  9.         style = elem.style;

  11.     name = jQuery.cssProps[origName] || (jQuery.cssProps[origName] = vendorPropName(style, origName));

  13.     // gets hook for the prefixed version
  14.     // followed by the unprefixed version
  15.     hooks = jQuery.cssHooks[name] || jQuery.cssHooks[origName];

  17.     // Check if we're setting a value
  18.     if (value !== undefined) {
  19.         type = typeof value;

  21.         // convert relative number strings (+= or -=) to relative numbers. #7345
  22.         if (type === "string" && (ret = rrelNum.exec(value))) {
  23.             value = (ret[1] + 1) * ret[2] + parseFloat(jQuery.css(elem, name));
  24.             // Fixes bug #9237
  25.             type = "number";
  26.         }

  28.         // Make sure that null and NaN values aren't set. See: #7116
  29.         if (value == null || value !== value) {
  30.             return;
  31.         }

  33.         // If a number was passed in, add 'px' to the (except for certain CSS properties)
  34.         if (type === "number" && !jQuery.cssNumber[origName]) {
  35.             value += "px";
  36.         }

  38.         // Fixes #8908, it can be done more correctly by specifing setters in cssHooks,
  39.         // but it would mean to define eight (for every problematic property) identical functions
  40.         if (!support.clearCloneStyle && value === "" && name.indexOf("background") === 0) {
  41.             style[name] = "inherit";
  42.         }

  44.         // If a hook was provided, use that value, otherwise just set the specified value
  45.         if (!hooks || !("set" in hooks) || (value = hooks.set(elem, value, extra)) !== undefined) {

  47.             // Support: IE
  48.             // Swallow errors from 'invalid' CSS values (#5509)
  49.             try {
  50.                 style[name] = value;
  51.             } catch(e) {}
  52.         }

  54.     } else {
  55.         // If a hook was provided get the non-computed value from there
  56.         if (hooks && "get" in hooks && (ret = hooks.get(elem, false, extra)) !== undefined) {
  57.             return ret;
  58.         }

  60.         // Otherwise just get the value from the style object
  61.         return style[name];
  62.     }
  63. }

can somebody tell me what is the purpose of the style method in jquery ? is it something internal to jquery ? or what is the purpose of this method ?