Each of these three components relates directly to the way Google processes and organizes websites to determine their ranking capacity in search queries. The technology behind a website is to ensure that search engines can crawl and index all your content in the right way. This means having a clean HTML code, properly structured URLs (without parameters, if possible), the correct HTTP status codes for the right type of web pages (so that a page not found results in a 404 code, not 200 or 30), proper XML sitemaps, etc. Most SEO audits will spend a lot of time on the technology of a website, and the platform on which a site is based will have a big impact on the SEO compatibility of a website's technological foundations in reality.
WordPress sites tend to check a lot of boxes right away, while sites that rely on them. NET can often be a total nightmare for SEO. Of course, this is just my approach to teaching SEO, and I suspect it has its flaws, as it's based on my own incomplete understanding of search engine technology. However, so far I think it has resulted in a clearer picture of SEO for both me and my students.
The relevance aspect of SEO analyzes the various elements of your content to ensure that search engines can interpret it correctly. Optimizing the HTML elements on every page of the website is a critical factor in search engine optimization. A key element of external SEO are backlinks, links from other sites to your website that show Google that other sites value your site. Many SEO solutions and tactics will be based on different pillars and processes, but you'll be surprised to see how many different SEO elements fit neatly into one of these three main areas.
I've been doing SEO for a long time (as a hobby for my own sites since the late 90s, professionally since 2004), and while hype and tactics come and go, I've learned that the basic elements of SEO remain the same. While search engines are very complex pieces of software, they are essentially made up of three different processes. These pillars are just the tip of the SEO iceberg, but they capture some of the most fundamental elements of SEO.