Digital marketing (DM) involves using digital channels like search engines, social media, mobile apps, and email to promote brands and services. DM offers benefits like reaching a large audience, allowing for instant communication, and being cost-effective. Common forms of DM include search engine optimization, social media marketing, pay-per-click advertising, cost per impression, affiliate marketing, and email marketing. Websites are collections of web pages written in HTML code to serve a purpose, and web browsers like Chrome and Mozilla display these pages in a human-readable format. Major search engines like Google, Bing, and Yahoo act as databases that index web content and return relevant results when users search with keywords.