Digital marketing is marketing that uses digital channels: search engines, social media, email, websites, apps, and display ads. It replaced much of traditional marketing — print, radio, television, direct mail — because it is cheaper, more measurable, and more targeted. A small business can run a Facebook ad campaign for a hundred dollars and see exactly how many clicks it generated.

The field includes several specialties. Search engine optimization (SEO) improves organic visibility. Search engine marketing (SEM) buys ads on search results. Content marketing attracts audiences with useful information. Social media marketing builds community and engagement. Email marketing nurtures leads. Influencer marketing borrows someone else's audience. Each has its own tactics, metrics, and best practices.

The advantage of digital is data. You can track impressions, clicks, conversions, and cost per acquisition in real time. That feedback loop allows rapid iteration. The disadvantage is noise. Digital channels are crowded, attention is scarce, and privacy regulations are tightening. Standing out requires more than a budget. It requires a clear message and a deep understanding of the audience.