IEC 61747-1-2:2014 gives the preferred terms, their definitions and symbols for liquid crystal devices, with the object of using the same terminology when publications are prepared in different countries. This first edition cancels and replaces the first edition of IEC 61747-1 published in 1998 and Amendment 1:2003. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) The former IEC 61747-1, Generic specification was divided into IEC 61747-1-1, Liquid crystal display devices - Part 1-1: Generic - Generic specification and IEC 61747-1-2, Liquid crystal display devices - Part 1-2: Generic - Terminology and letter symbols; b) In this part of IEC 61747, new terms have been added and some of the terms and the definitions have been updated.