/*#default-div {
  background:gray;
}

#fixed-div{
 background-color: lime;
  position: fixed;
}
body{
  height: 2000px;
}*/

#parent-div{
  position:relative;
  background: orange;
   height: 1500px;
}
#default-div{
  background: blue;
}
#sticky-div{
  background:green;
  position: sticky;
  top: 10px;
}