This document provides an overview of high performance liquid chromatography (HPLC). It discusses the basic principles of chromatographic separation and defines key terms like retention time and resolution. It also describes different HPLC techniques including normal phase, reversed phase, ion exchange, size exclusion, and ion-pair chromatography. The document outlines the typical instrumentation used in HPLC including the pump, injector, chromatography column, detectors, and data collection system. It provides details on how each component works and its purpose. Overall, the document serves as a comprehensive introduction to HPLC principles, methodology, and instrumentation.