I used to think the two was the same thing until I made a research. Digital marketing is an umbrella term that encompasses all types of marketing activities that a brand performs digitally, both online and offline, to promote their services or products. Social media marketing, on the other hand, is one of the channels of digital media marketing. It involves marketing on social media platforms such as Facebook, Instagram, Twitter, etc. While Social media marketing is only one aspect of digital marketing. It implies the use of social media channels such as Facebook, Twitter, Instagram, YouTube, Goggle+, Snapchat, etc. to marketing your products, services, or brand. Typically, it involves engagement with your target audience, followers, seeking industry influencers, posting fresh and unique content, arranging contests and adopting a variety of other means to grab the attention of the audience present on different social media channels.