On Page is one of the most fundamental facets of SEO, and is basically considered table stakes - you need to be getting the basics right if you expect to compete in competitive spaces. On Page SEO remains one of the main methods for communicating to search engines the subject matter of a given URL. There are a number of fundamental elements that need to be handled correctly, for maximum benefit.
Most modern CMS platforms allow you to control and adjust all the major On Page SEO elements, so making fixes or amendments is achievable for SEOs of basically any level.
The on page fundamentals are typically the page <title>, the meta description and the <h1> tag.
The page <title> is an important factor for SEO, as it provides the clearest opportunity to communicate 'what the page is about', both to search engines and users alike.
As a result, you generally want your title tags to be both descriptive and keyword/topic rich. Often, the title is automatically populated across a website via a script or CMS template, which is how a lot of the issues below arise.
In and of itself, the meta description actually has no direct impact upon SEO, in terms of rankings at least. However, the content of a meta description is still very important, as it is your main opportunity to convince a searcher to click through to your web page from the search results.
Since search engines can and will auto-populate a meta description, they can sometimes be overlooked, but optimizing meta descriptions remains a reliable way to generate more traffic from search.
Often, meta descriptions are auto-generated using on-page content, or simply left blank, which can lead to issues.
While the importance of the <h1> to SEO is debatable, it is still a worthwhile endeavour to spend time making headers as useful as possible, as this improves content structure, which can have an impact upon user experience.