Infectious diseases are illnesses caused by pathogens such as bacteria, viruses, fungi, or parasites, and they remain a major cause of morbidity and mortality worldwide. Drug discovery here focuses on antivirals, antibiotics, antifungals, and antiparasitics. For digital‑health stakeholders, defining this term frames why AI platforms may prioritise infectious‑disease targets, especially in the context of emerging threats and antimicrobial resistance.