On Page Search Engine Optimization or On Page SEO refers to everything used or contained within the rendered HTML document that makes up the web page that is used by a search engine algorithm to place your page in its index. This includes both visible and invisible elements. The pages content and its formatting are examples of the former, Title Tags and Meta tags are examples of the latter.
These are not the only factors, but for UCANSEO grouping purposes, we will keep all On Page SEO, On Site SEO and Offsite SEO in separate groups.