World history is a field of academic study that emerged in the 1980s to examine history from a global perspective rather than focusing on individual cultures or nations. It is distinct from comparative history, which looks at multiple cultures and nations but not on a global scale, and from diplomatic or international history. The document also provides background on the early civilization that emerged along the Indus River in India around 2500 BC and the subsequent Indo-European invasion and development of Hinduism.