Digital marketing involves marketing products and services using digital technologies like the internet, mobile phones, and display advertising. Some key points covered in the document include: - Types of keywords for search engine optimization like short tail, long tail, branded, and geo-targeted keywords. - On-page SEO elements like meta titles, descriptions, internal and external links, anchor text, and social snippets. - Off-page SEO topics such as do follow and no follow links, plagiarism, website audits including robots.txt files, schema markup, and website speed and responsiveness.