More than a one-line copyright — a large footer that doubles as a sitemap. Columns are usually grouped by category ("Product," "Company," "Resources," "Legal"), each with five to eight links stacked vertically. A logo and one-line tagline sit up top, often alongside a newsletter field.
Footer links rarely get clicked, but they do two things: they thicken the site's internal link graph for SEO, and they signal that a real company is behind the product (careers, about, terms of service). The very bottom row usually holds the copyright year, social icons, and a language/region switcher.
Uneven link counts per column make the bottom edge look ragged — merge a category with fewer than three links into a neighbor instead of giving it its own column. And a link pointing to a placeholder `#` gets caught the instant a visitor clicks it.
When to use
Use once the site has more than about ten pages, or needs to surface company info like careers and legal terms. A single-page product is fine with a short, single-line footer.