background: url('../img/category_bg.jpg') cover no-repeat;
background can be used to set the values for one or more of: background-clip, background-color, background-image, background-origin, background-position, background-repeat, background-size, and background-attachment.
background: color position/size repeat origin clip attachment image|initial|inherit;
background: url(https://www.google.ru/images/branding/googlelogo/2x/googlelogo_color_120x44dp.png) 21px 1px/110px 50px no-repeat;