LinkedIn is a social media site that allows users to connect with contacts, build their professional profile, and find job opportunities. It provides features for jobs, contacts, and profiles to help with digital presence. Digital presence is important nowadays as the world moves online, allowing businesses to reach new audiences, demonstrate expertise, and build relationships to gain customers. The document also discusses personal experience using LinkedIn to get in contact with important business contacts, publish and share knowledge, and support personal learning through accessing various articles.