This document defines inflation and describes its types including creeping, walking, running, galloping, and hyper inflation. It lists causes of inflation such as demand pull, cost push, money supply expansion, population increase, and credit expansion. Methods to measure inflation and India's inflation rates are presented. Reasons for India's high inflation in the 1990s and post-1991 are discussed, including balance of payments changes, fiscal deficit, rupee depreciation, and global oil price increases. In conclusion, pre-reform inflation was due to domestic factors while post-reform inflation is more influenced by global scenarios.