E-health refers to use of information and communication technologies to improve or enable health and healthcare. E-health broadens the scope of healthcare delivery; citizens are in the center of services and services are offered by information systems often via the Internet. In this chapter e-health systems are classified on the basis of their use and their functionality and the use is discussed from the viewpoints of citizens and health professionals. Citizens are increasingly using Internet and e-health systems to search for medicine or health-related information, and they become better informed and may take more responsibility of their own health. Health professionals are more reluctant to use the Internet and e-health systems in physician-patient communication due to the power and responsibility problems of decisions. In the future the sociotechnical nature of e-health should be considered and future systems developed for real use and user environment with user acceptable technology.