Although no single theoretical framework can fully explain the effects of communication technologies, several theories, models, and constructs offer insights into their use and implications for health and health communication. The term communication technology refers to several classes of tools that make possible mediated forms of communication between two or more individuals. Popular contemporary communication technologies include, but are not limited to, e-mail, text messaging, instant messaging, as well as social media such as video-sharing Web sites, photo-sharing Web sites, social network Web sites, blogs, microblogs, and online discussion groups. Four theoretical frameworks and four key constructs can explain the use and implications of communication technologies for health and health communication.