Language change is the modification of linguistic structures and usage patterns within a speech community across generations. This academic field investigates the mechanisms, motivations, and consequences of diachronic variation across all levels of linguistic analysis, including phonetics, phonology, morphology, syntax, semantics, and the lexicon. It is characterized by its dynamic, ongoing nature, influenced by factors such as internal linguistic pressures, social interaction, language contact, and cognitive processes. The study of language change is crucial for understanding language evolution, reconstructing historical linguistic relationships, and gaining insights into the cognitive and social factors that shape human communication systems.