Constrain the movement of each draggable by defining the boundaries of the draggable area. Set the axis option to limit the draggable's path to the x- or y-axis, or use the containment option to specify a parent DOM element or a jQuery selector, like 'document.'

<!doctype html>
<html lang="en">
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>jQuery UI Draggable - Constrain movement</title>
  <link rel="stylesheet" href="//">
  <link rel="stylesheet" href="/resources/demos/style.css">
  .draggable { width: 90px; height: 90px; padding: 0.5em; float: left; margin: 0 10px 10px 0; }
  #draggable, #draggable2 { margin-bottom:20px; }
  #draggable { cursor: n-resize; }
  #draggable2 { cursor: e-resize; }
  #containment-wrapper { width: 95%; height:150px; border:2px solid #ccc; padding: 10px; }
  h3 { clear: left; }
  <script src=""></script>
  <script src=""></script>
  $( function() {
    $( "#draggable" ).draggable({ axis: "y" });
    $( "#draggable2" ).draggable({ axis: "x" });
    $( "#draggable3" ).draggable({ containment: "#containment-wrapper", scroll: false });
    $( "#draggable4" ).draggable({ containment: "parent" });
  } );
<h3>Constrain movement along an axis:</h3>
<div id="draggable" class="draggable ui-widget-content">
  <p>I can be dragged only vertically</p>
<div id="draggable2" class="draggable ui-widget-content">
  <p>I can be dragged only horizontally</p>
<h3>Or to within another DOM element:</h3>
<div id="containment-wrapper">
  <div id="draggable3" class="draggable ui-widget-content">
    <p>I&apos;m contained within the box</p>
  <div class="draggable ui-widget-content">
    <p id="draggable4" class="ui-widget-header">I&apos;m contained within my parent</p>