The chapter aims to inform researchers and speech language pathologists on current definitions, key constructs, tenets, available resources, and challenges in the field, serving to tighten the existing, but overall loose, connection between the study of child bilingual phonological development cross-linguistically and the diagnosis, assessment, and therapy protocols in the context of bilingual children’s speech disorder. The chapter provides an overarching review of apposite literature to date, discussing the evolution of terms and key issues, and their relevance in bridging the gap between psycholinguistics research, theory, and clinical practice for bilingual children’s speech sound disorders nowadays. Ultimately, the chapter utilizes existing knowledge to project the canonical perspective that a universal classification of phonological disorders can be informed only by a single mechanism driving its manifestations across children, albeit one that needs to take into consideration every child’s spot on the spectrum of disorder, and on the global map of linguistic and cultural diversity. Gaps and future directions are integrally sketched.