This document provides an overview of liquefied natural gas (LNG) including its history and key components. It discusses the differences between LNG, LPG, NGLs, CNG and PNG. The main units used to measure natural gas are described. The key components of an LNG liquefaction plant including pretreatment, refrigeration, storage and regasification are summarized. Specific liquefaction processes like the C3 MR, AP-X and cascade cycles are also outlined. The document concludes with sections on LNG transportation, global demand trends, and modeling an example Egyptian LNG plant.