The Indo-European languages are a family of several hundreds related languages and dialects. There are about 445 Indo-European languages with over two-thirds (313) of them belonging to the Indo-Iranian branch only. The Indo-European family includes most major current languages of Europe, and parts of Western, Central and South Asia.
Membership of these languages in the Indo-European language family is determined by genetic relationship, meaning that all members are presumed descendants of a common ancestor. (The word "genetic" here has nothing to do with human genetics; it refers to relationships between languages.) Membership in the various branches, groups and subgroups of Indo-European is also genetic.
While similarities are still visible between the modern descendants and relatives of these ancient languages, the differences have increased over time.
Today, Indo-European languages are spoken on all inhabited continents, by almost 3 billion native speakers. The largest number by far for any recognized language family. Of the 20 languages with the largest numbers of native speakers 11 are Indo-Europeans: Spanish, English, Hindi, Portuguese, Bengali, Russian, Punjabi, German, French, Marathi, and Urdu.