In computing, Internationalization and localization (also spelled internationalisation and localisation, see spelling differences) are means of adapting computer software for non-native environments, especially other nations and cultures. Internationalization is the process of designing a software application so that it can be adapted to various languages and regions without engineering changes. Localization is the process of adapting software for a specific region or language by adding locale-specific components and translating text.
Due to their length, the terms are frequently abbreviated to i18n (where 18 stands for the number of letters between the i and the n in internationalization, a usage coined at DEC in the 1970s or 80s) and L10n respectively. The capital L on L10n helps to distinguish it from the lowercase i in i18n.
Reference:
http://en.wikipedia.org/wiki/I18n#Alternative_names
