Virtual coaching applications, designed to facilitate behavior change through adaptive coaching activities, hold promise for personalized interventions, particularly in healthcare. While existing literature explores various aspects of virtual coaches (VCs), there is a lack of comprehensive conceptual analysis, and inconsistent terminology further complicates their understanding. The present paper aims to demonstrate the ongoing work on systematically categorizing and describing the components of VCs and, thereby, creating a reference model reusable for different contexts. Based on a systematic literature review, concepts related to VC interventions will be derived, categorized, and linked to each other, forming a unified framework that could simplify the process of designing VCs and provide the foundation for dedicated building tools in terms of low/no-code platforms. Moreover, the work contributes with a consolidated terminology, and the proposed model may also be used to identify underexplored research areas, enhancing research opportunities in the field.