Every CSS declaration includes a property / value pair. Depending on the property, the value can include a single integer or keyword, To a series of keywords and values with or without units. There are a common set of data types — values and units — that CSS properties accept. Below is an overview of most of these data types. Refer To the page for each value type for more detailed information....values that can be defined by the web developer, like keyframe animations...wanted to include a background image, you might use either of the...