Because of the proximity of people speaking a variety of different languages in Europe, businesses often provide access to multiple languages. The user should be able to return to the home page and select the language as you do for the first screen on ATMs. The Mozilla Locale model is intended to provide programmers with a strategy for handling locale preferences in a way that supports our multilingual model of web browsing. In the most general case, a locale is a set of user preferences that are tied to the language and location of the particular user. The preferences captured by a locale are usually those things that change across languages and regions but aren't necessary changed by the user.
Common examples are date and currency formatting.
A locale can also be a specific instance of this collection of preferences. 4.2 Locale Category A locale is a collection of different properties. A locale category is a particular property that can be extracted from a locale. Traditionally the properties extracted from a locale have been called categories, so we continue this usage. A locale model is an abstract design about what entities in a piece of software need to store and maintain locale information.