Digital marketing uses electronic media like the web, email, and wireless devices along with customer data to build relationships and facilitate online exchanges. It involves key components like search engine optimization (SEO), pay-per-click (PPC) advertising, social media marketing (SMM), email marketing, display ads, affiliate marketing, content marketing, and online reputation management (ORM). SEO improves the visibility of websites in organic search results, while PPC allows control over campaign advertising and tracking of efficiency. SMM utilizes social media platforms for communication and interaction, and email marketing promotes products through subscriber mailing lists.