OnPage SEO (also known as on-site SEO) is the practice of optimizing elements on a website (as opposed to links elsewhere on the Internet and other external signals collectively known as “off-site SEO“) in order to rank higher and earn more relevant traffic from search engines. On-site SEO refers to optimizing both the content and HTML source code of a page.
Beyond helping search engines interpret page content, proper on-site SEO also helps users quickly and clearly understand what a page is about and whether it addresses their search query. In essence, good on-site SEO helps search engines understand what a human would see (and what value they would get) if they visited a page, so that search engines can reliably serve up what human visitors would consider high-quality content about a particular search query (keyword).
The ultimate goal of on-site SEO can be thought of as attempting to make it as easy as possible for both search engines and users to:
- Understand what a webpage is about;
- Identify that page as relevant to a search query or queries (i.e. a particular keyword or set of keywords);
- Find that page useful and worthy of ranking well on a search engine results page (SERP).