Technical SEO is the part of SEO that takes care of the site's infrastructure to ensure search engines can crawl, index and understand the content correctly. It covers aspects such as loading speed, mobile responsiveness, security (HTTPS), XML sitemap, robots.txt, canonical tags and schema markup.
Google's Core Web Vitals are a central part of Technical SEO. They measure three aspects of the user experience: LCP (Largest Contentful Paint, the loading speed of the largest visible element), INP (Interaction to Next Paint, responsiveness to interactions) and CLS (Cumulative Layout Shift, the page's visual stability).
At Netlinks, Technical SEO is the "T" pillar of the NETLINKS Method. It works as the foundation: if the site has technical problems, no amount of content or link building will make up for it. That is why periodic technical audits are part of the process for every client.