javascript - What does JQuery UI add here? -

Recently, I saw a video on YouTube where a person created a horizontal slider using JQuery and JQuery UI. I have successfully rebuilt the slider, however, I do not understand what the JQuery UI actually does. If I remove it, the slider will not work. If any of you tell me what it is that the jQuery UI adds here, then it will be really appreciated!

This is the code for the slider:

HTML

  & lt; Body & gt; & Lt; Div class = "slider" & gt; & Lt; Img id = "1" src = "1.jpg" & gt; & Lt; Img id = "2" src = "2.jpg" & gt; & Lt; Img id = "3" src = "3.jpg" & gt; & Lt; / Div & gt; & Lt; Script src = "../../../user/dave/download/jquery-1.11.1.min.js" & gt; & Lt; / Script & gt; & Lt; Script src = "../../../User / Dave / Desktop / jquery-ui.min.js" & gt; & Lt; / Script & gt; & Lt; Script src = "behavior.js" & gt; & Lt; / Script & gt; & Lt; / Body & gt;  

CSS

.slider {width: 600px; Height: 400 pixels; Hidden flurry; Margin: 30 Auto; } .slider img {width: 600px; Height: 400 pixels; display none; } ($ "(. Slider # 1") show ("fade")

JQuery

  function slider () , 500); $ (". Slider # 1"). Delay (5500). Hyde ("Slide", {Direction: 'Left'}, 500); Var sc = $ (".md slider"). Shape (); Var calculation = 2; Set (interline) (function () ($ (". Slider #" + count). Show ("slide", {direction: 'right'}, 500); $ (". Slider #" + count). 5500) Hide ("slide", {direction: 'left'}, 500); if (count == SC) {count = 1;} and {count = count + 1;}}, 6500);} $ (document) ) .ready (function () {slider ();});  

Like I said, at the slider exactly how I want to do it, I understand the code and how it works I do not understand why I want JVC UI for this What methods / functions / etc does it add here? Why does not it work without the jQuery UI?

< P> The code is using S which is not available in JQuery Core