Definition
The practice of improving a website's organic search ranking through content, technical signals, and backlinks. Distinct from paid advertising; aims for unpaid clicks.
Why it matters
SEO matters to an owner because the clicks it earns keep arriving after the work is done, unlike ads that stop the moment you stop paying. It's how a business shows up when someone is actively searching for what you sell, which is usually the highest-intent traffic you can get. The catch is patience: results build over months rather than days, and it's easy to pour effort into a site with no way to tell what's actually moving the ranking.