Inside the style sheet, we can access ids with a hash (#). For example, if you gave one of your headings an id, type #Header to use it as a selector. Selectors allow you to set CSS rules for unique elements, and element types, and classes.

Let's say we want a heading to be displayed in bold on a red background. Use the properties font-weight and background and give them respective values. In this case, the CSS rule would look like this:

#Header {

font-weight: bold;

background: rgb(255, 0, 0);

}