Addressing the need for more comprehensive research on social and service robots, this chapter offers a systematic understanding of the realm of companion robots and their role in fostering well-being. An integrated framework is proposed that highlights the stimulus-organism-response process, resulting in five dimensions - interface (S), interaction (S), companionship (O), support (R) and well-being (R) - and 13 sub-dimensions. We present three illustrative cases - Vector, Joy For All and Miko - that provide additional details and arguments in relation to our integrative framework.