The purpose of localization during translation is to adapt your text to the needs of a particular language or culture. After a document is localized is should have the “look-and-feel” of the target language. It should appear that the information was actually written or developed within the local culture.
Consider the following translation of a document from Japanese to English. You want your document to meet all of the rules of the language, the culture, and the region. Without more information, however, this is not possible. The English language is too vast. Some machine translators have accounted for language variants, as have some CAT systems, but the majority of computers simply translate to “English”. Sometimes there is a choice of British English instead of American English, but even this is not universal. The same is true for Portuguese, where European and Brazilian Portuguese have any number of differences.
In Spanish, there are many variations in the language, and not all countries follow the rules of Castillian Spanish within their official language. Even within Spain there are distinct language groups such as Catalan and Basque (which is actually nothing like Spanish). The Spanish of the Canary Islands has many Portuguese influences, Latin American and Caribbean Spanish are both close to Castillian Spanish, but still different than each other. Argentina and Uraguay speak a variant that is almost closer to Italian than Spanish.
While there are dozens of Arabic dialects, and Chinese dialects number in the hundreds, all official documents in these two languages are written in Literary Arabic and Mandarin, respectively. This makes translation to and from these languages much easier.
When selecting a translation service provider, it is important to look beyond the direct language pairs listed on the website and ask questions about the ability of their translators to localize your documents when the source language has distinct variations. An American may speak English, but it would be almost impossible for them to translate a document into a Scottish dialect