Answer
A pseudo-class selects an element state; a pseudo-element selects or creates a stylable part. • `:hover` matches an element while the pointing device designates it. • `::before` creates a generated first child box. • Pseudo-elements normally use two colons.
💡 Simple Example
a:hover { text-decoration-thickness: 3px; }
a::before { content: "→ "; }
⚡ Quick Revision
Pseudo-classes describe state; pseudo-elements address a part or generated box.