Search engine optimization (SEO) is the practice of making a website more visible to people searching for relevant terms on Google and other search engines. SEO services are the specific, repeatable activities an agency or consultant performs to move that visibility forward.
The term gets used loosely, which creates confusion. A business owner Googling 'SEO services' will encounter everything from $99/month automated packages to six-figure retainers — and both call themselves the same thing. The difference is almost always in what work is actually being done and whether that work addresses the factors Google genuinely uses to rank pages.
Google's ranking systems evaluate hundreds of signals, but the work that moves the needle consistently falls into a few well-understood categories: the technical health of the site, the relevance and quality of on-page content, the credibility signals from other websites linking to yours, and — for businesses serving specific geographies — local search signals.
SEO services are delivered in two main structures:
- Retainer engagements — ongoing monthly work covering multiple service types simultaneously, suited to businesses that want to grow and defend rankings over time.
- Project-based engagements — scoped work with a defined start and end, such as a technical audit and remediation, a content sprint, or a site migration. Suited to businesses with a specific, bounded problem.
Neither model is inherently better — the right structure depends on where your site is starting from and what you're trying to achieve. Most businesses in competitive markets need ongoing work to see compounding results.