A strong, light, synthetic polymer. The name comes from the number of carbon atoms in the repeating units, 6 and 10 in this case. There are other types of Nylons in which the repeating units contain numbers of carbon atoms different from 6 and 10. For example, an important commercial Nylon is called '6-6' in which each repeating unit contains 6 carbon atoms. Incidently, the repeating units also contain hydrogen (H), nitrogen (N), and oxygen atoms (O) in addition to carbon (C) atoms