Technical SEO is about the site itself rather than the words on the page. If search engines cannot reach a page, read it or decide which version is the real one, good content will not help.
Common areas: making sure important pages are not blocked (robots.txt), keeping an accurate XML sitemap, setting a canonical URL where duplicates exist, using proper redirects when URLs change, fast loading, mobile-friendly layouts, clean internal links, and valid structured data. It also includes watching for errors and for pages accidentally set to stay out of the index.
The best habit is to check what search engines actually see, using the reports in a search console and a crawl of your own site, instead of assuming. Fixing one broken template can correct thousands of pages at once.
Related: Crawling, Indexing, Search Engine Optimization, AI-Ready Website.