There is no one, commonly accepted definition of either ‘telehealth’ or ‘telemedicine’. It is also sometimes referred to as ‘digital health’, ‘virtual health’ or ‘connected health’. The American Telemedicine Association describes it succinctly as “technology-enabled health and care management and delivery systems that extend capacity and access.” https://www.americantelemed.org/resource/why-telemedicine/
The Maryland Health Care Commission describes it this way: “Telehealth is the use of two-way audio and video and other forms of telecommunication technology, including mobile communication devices and remote monitoring devices, to share medical information with the goal of improving a patient’s health status. The definition of telehealth is broader in scope than that of telemedicine and encompasses both clinical and non-clinical services, such as provider training, case management support, administrative meetings and continuing medical education.” https://mhcc.maryland.gov/mhcc/pages/hit/hit_telemedicine/hit_telemedicine.aspx
An easier way to think about it is to say that telehealth is the use of telecommunication technology to deliver and support health care services to a patient who is not in the same location as the health care provider and to use telecommunication technology to share medical information.
For some examples, see what Johns Hopkins Telemedicine has to say: “Connecting Patients to Exceptional Virtual Care”