5. What is cascading in CSS?

Cascading in CSS refers to the way the browser applies different CSS rules to HTML elements based on specificity, order in the style sheet, and importance (!important). The cascade determines which rules take precedence if there are conflicts.

/* Example of cascading */
p {
    color: red; /* Rule 1 */
}

p {
    color: blue; /* this rule wins because it is later */
}

p.important {
    color: green !important; /* this rule will win over any other */
}