Strategic Search Engine Optimization has 3 main components
On-site Optimization - On-site optimization is all about the content, structure, and layout of your site. Google and other search engines crawl your site to get an understanding of what it's about (and how authoritative it is), so the information it finds on your website can have a big impact in how it ranks pages on your site for relevant search queries.
Off-site Optimization -
Everything else in your SEO campaign should be focused on off-site authority building, meaning building a presence and relationships on external sites and platforms. The biggest tools Google uses to evaluate this "authoritativeness" are inbound links from such external sources. The more inbound links you have pointing to your site from high-authority sources, the better your perceived authority, and the higher your website will rank in search engines.
Compelling and Relavant Content - Your content shows off your expertise, helping users trust you, and gives you a platform for conversion by including calls to action at the end of your pieces. It can also serve as fuel for your social media or email marketing campaigns.