A nanobody is a compact antibody fragment derived from the heavy-chain-only antibodies present in camelids like llamas and camels. Also known as VHH or single-domain antibodies, nanobodies consist of a single functional domain, making them the smallest naturally occurring antigen-binding units. Unlike conventional antibodies, nanobodies lack light chains and exhibit a unique structure that contributes to their versatility and exceptional characteristics. With a size of around 15 kDa, nanobodies penetrate tissues effectively and bind to hidden epitopes. Engineered for stability, they demonstrate resistance to harsh conditions, ensuring robust performance in diverse experimental settings. High solubility further adds to their reliability. Nanobodies exhibit remarkable specificity and affinity for their target antigens, enabling precise and sensitive detection. Their production involves library construction from genetic material and in vitro selection techniques. Nanobodies find applications as research tools in molecular imaging, protein crystallization, and structural biology studies. In diagnostics, they contribute to the development of highly sensitive assays, while in therapeutics, their potential includes targeted drug delivery and cancer treatment. In summary, nanobodies represent a pioneering class of antibody fragments with unique properties, reshaping possibilities in molecular research and various applications.