CSS allows you to specify background styles for elements in your HTML documents. Here are some of the most common ways to specify background styles in CSS:

1. background-color: This property allows you to specify a solid color as the background of an element. For example:

body {
    background-color: lightblue;
}

2. background-image: This property allows you to specify an image as the background of an element. For example:

body {
    background-image: url("myimage.jpg");
}

3. background-repeat: This property allows you to specify how the background image should be repeated, if at all. The possible values are:

• repeat: The image is repeated both horizontally and vertically.
• repeat-x: The image is repeated horizontally only.
• repeat-y: The image is repeated vertically only.
• no-repeat: The image is not repeated.

4. background-position: This property allows you to specify the position of the background image. You can specify the position using either keywords (such as top, center, or bottom) or lengths (such as 10px or 2em).

body {
    background-position: center;
}

background-attachment: This property allows you to specify whether the background image should scroll with the rest of the content or remain fixed in place. The possible values are:

scroll: The image scrolls with the rest of the content.
fixed: The image is fixed in place.

You can use these properties, either individually or in combination, to specify a wide range of background styles for your HTML elements.