how to set a background image in css from file code example

Example 1: background image

div {
  background-color: #ffffff;
  background-image: url("img_tree.png");
  background-repeat: no-repeat;
  background-attachment: scroll|fixed|local|initial|inherit;
  background-position: right top  |  x% y%  |  xpos ypos;
  background-clip: border-box|padding-box|content-box|initial|inherit;
  background-size: auto|length|cover|contain|initial|inherit;
}
//shorthand:
div {
  background: #ffffff url("img_tree.png") no-repeat right top;
}

Example 2: CSS adding background image from file

/* The first method using an image on your server */
background: url('img/someimage.jpg');

/* The second method using an image hosted on another server */
background: url('http://www.someimage.com/someimage.jpg');

/* A third method that allows the site to determine protocol instead of explicitly defining it */
background: url('//www.someimage.com/someimage.jpg');