Content is King is often said. A statement that is used by many online marketers and agencies. It does not only content (text / information) but relevant and unique content. Relevant and unique content is important throughout the site: search engines like Google do not look to individual pages within a website, but form an image in response to all pages within a website. Some "bad pages" (pages without content or pages without unique / relevant content) have a negative effect on the entire website (including pages with unique and relevant content). The content should be consistent with the target audience of the website visitors: you need a content strategy that is written to the target and where you focus is on some important keywords that fit the audience. A comprehensive keyword research is essential prior to determining the most relevant SEO structure.
Content is not only about writing unique and relevant texts. Important elements within the content, the implementation of rich snippets, the unique creating meta tags, use of heading tags, a distinct URL structure that matches the content, alt text for images and use text elements (bold text, links to relevant pages to make it easier to navigate for visitors), etc.