Click chemistry has become an efficient and versatile approach for linking complex biomolecular structures, with broad application in bioconjugation. This chapter provides an overview of core concept of click chemistry including its fundamental principles and outlines different types of click and click-like reactions. We also discuss recent advances such as photoclick chemistry and describe how light drives the reactions. Furthermore, bio-click chemistry is introduced, highlighting the integration of biocatalysis and click chemistry principles. Through these topics, we demonstrate how click chemistry has become an essential tool for modifying biomolecules, with important applications in biomedical research, diagnostics, and material science. This chapter aims to enlightens readers about the current landscape and prospects of click chemistry in bioconjugation methodologies.