The cloud continuum concept has drawn increasing attention from practitioners, academics, and funding agencies and been adopted progressively. However, the concept remains mired in various definitions with different studies providing contrasting descriptions. Therefore, to understand the concept of cloud continuum and to provide its definition, in this work we conduct a systematic mapping study of the literature investigating the different definitions, how they evolved, and where does the cloud continue. The main outcome of this work is a complete definition that merges all the common aspects of cloud continuum, which enables practitioners and researchers to better understand what cloud continuum is.INDEX TERMS Cloud continuum, edge, Fog.