Differentiate between on-page and off-page optimisation.
On-page SEO involves all the on-site techniques you can employ to ensure a webpage will rank on a SERP, and it can also help determine how well that page ranks. On-page SEO deals with the pages on a website, both in regards to content and the backend structure of a site.
Activities included optimizing Title tags, Meta descriptions, Headings, URL structure, Alt text for images, Site speed, Internal links.
Off-page SEO is the actions taken outside your website that impact search engine rankings. off-page SEO focuses on increasing the authority of your domain through content creation and earning backlinks from other websites.
Off-page consists of link-building from guest blogging, outreach, participating in forums, and leaving comments on blogs.