Digital marketing is about communicating with target audiences using digital platforms like social media, blogs, and mobile marketing. It has several key components - the audience, content, context/message, and the medium of the internet. Digital marketing can be segmented into search engine marketing and social media marketing. It is more affordable, effective, and easy than traditional marketing. Common digital marketing tactics include SEO, content creation, social media engagement, email marketing, and advertising on platforms like Google, Facebook, and YouTube.