Digital marketing covers every channel a brand uses to reach customers online: search engines, social media, email, websites, and paid ads. Marketers typically organize these into three categories -- owned media (your website, email list, social accounts), earned media (press mentions, shares, reviews), and paid media (ads you pay for). Successful campaigns map these channels to the customer journey: awareness, consideration, conversion, and retention/loyalty. Understanding this framework helps you choose the right channel for the right goal instead of chasing every platform at once.