Background The field of Internet-supported therapeutic interventions has suffered from a lack of clarity and consistency. The absence of professional leadership and of accepted governing approaches, terminology, professional standards, and methodologies has caused this field to be diffused and unstructured. Numerous terms have been used to label and describe the activities conducted over the Internet for mental and physical health purposes: web-based therapy, e-therapy, cybertherapy, eHealth, e-Interventions, computer-mediated interventions, and online therapy (or counseling), among others. Methods Following a comprehensive review, we conceptualized Internet-supported interventions, using four categories based on prime practice approaches: web-based interventions, online counseling and therapy, Internet-operated therapeutic software, and other online activities (e.g., as supplements to face-to-face therapy). We provide a working definition and detailed description of each category, accompanied by numerous examples. Conclusions These categories may now serve as guiding definitions and related terminologies for further research and development in this emerging field.