Indo-European refers to a large family of languages that includes many of the languages spoken in Europe and parts of Asia. This family encompasses languages such as English, Spanish, Hindi, and Russian, all of which share a common ancestral language known as Proto-Indo-European. The study of Indo-European languages helps linguists understand the historical connections between different cultures and societies. By analyzing similarities in vocabulary, grammar, and phonetics, researchers can trace the evolution of languages and gain insights into the migration and interaction of ancient peoples.