On-page SEO, or on-site SEO, refers to a website's search engine optimization efforts that are done on the website itself. This includes keyword optimization for content, images, titles, text, and meta descriptions to improve a website's ranking on search engines such as Google and Bing. This is all done to improve your page rank and ultimately to increase traffic and sales. On-page SEO is important because it is the link between you and potential customers!
Search engines such as Google and Bing use algorithms, which are very complicated mathematical equations, that help determine which websites and pages to display on a search engine results page. On-page SEO is done to satisfy certain aspects of these algorithms. These include content relevancy, authority, and keyword use. Relevance is measured by how well the search query matches your website and content. For example, if you offer plumbing services in Toronto and have done the appropriate SEO, and if someone searches for "Plumber Toronto," your website should appear in the results with the appropriately optimized page. Authority, which measures a website/page's level of trustworthiness, is measured by the quantity and quality of inbound links, performance, structure, and the overall credibility of your website.
On-page SEO alone is not enough; off-page SEO techniques must also be utilized to ensure the success of your website and its goals. Click here to learn about on-page SEO's counterpart: Off-Page SEO.