- adding basic META tags
- adding Open Graph META tags
- adding Facebook META tags and sharing image(s)
- website listing on Google Search (Google Search Console)
- website listing on Bing Search (Bing Developer Center)
- adding Google Analytics
- decreasing page load time
- W3 validation
Search engine optimization (SEO) is the process of affecting the visibility of a website or a web page in a search engine's unpaid results—often referred to as "natural," "organic," or "earned" results. In general, the earlier (or higher ranked on the search results page), and more frequently a site appears in the search results list, the more visitors it will receive from the search engine's users. SEO may target different kinds of search, including image search, local search, video search, academic search, news search and industry-specific vertical search engines.
If you need more information, please check the Wikipedia article: https://en.wikipedia.org/wiki/Search_engine_optimization
Please message me if any question.