Greenberg's classification is a system used to categorize languages based on their genetic relationships. It was developed by linguist Joseph Greenberg in the mid-20th century. The classification groups languages into families, which share a common ancestor, helping linguists understand the evolution and connections between different languages. Greenberg's approach emphasizes the importance of linguistic features, such as vocabulary and grammar, to establish these relationships. His classification includes major language families like Indo-European, Sino-Tibetan, and Afro-Asiatic, providing a framework for studying the diversity and history of human languages across the globe.