What is the difference between <div> and <span>?

The key difference is their default display type. <div> is a block-level element — it takes up the full width available and starts on a new line, making it suitable for grouping and laying out large sections of content. <span> is an inline element — it only takes up as much space as its content and does not break the flow of text, making it suitable for styling or grouping small pieces of text within a line. Both are generic container elements with no semantic meaning (use semantic elements like <section> or <em> when the content has a specific purpose).