Onpage SEO refers to all search engine optimisation measures that are carried out directly on your own website in order to improve the ranking of the website in search engine results. It focuses primarily on optimising the content and structure of the website in order to increase the relevance and usefulness of the website for users and search engines.

Onpage SEO can be done in various ways, such as optimising titles, meta descriptions and headings, using relevant keywords and phrases, improving the readability and structure of content, optimising images and videos, using internal links, optimising loading speed and improving the user experience.

Optimising the content and structure of the website is crucial for search engine optimisation as it helps search engines understand the content of the website and display it for relevant search queries. A well-optimised website that provides useful and relevant content for users is also more likely to be rated positively by search engines and users.

However, it is important to note that on-page SEO is only one part of search engine optimisation and that off-page SEO measures such as building backlinks from other websites to your own website are also important to improve the ranking of a website in the search engine results.

Overall, on-page SEO is an important search engine optimisation strategy to improve a website's ranking in search engine results. It requires careful planning and implementation to ensure that the website is useful and relevant to users and search engines and that it provides a positive user experience.