The phrase above is part of a quotation attributed to playwright George Bernard Shaw, which describes the differences between British and American English. When requesting translation services, it is vitally important to specify which variant of the target language you need, and give information about the target audience. Otherwise, the effect might not be as you intended, or you may even alienate the very people that you wish to influence.
Here is a brief summary of the differences between the two ‘languages’.
Spelling
Aside from the well-known examples such as colour/color, grey/gray and centre/center, there also differences in specialised fields such as financial (cheque/check) and automotive (tyre/tire).
Vocabulary
A great example is the adaptation (technical term = localisation) of the Harry Potter series for an American audience, when a number of things were changed from the original text. Some examples can be found here. Even the title was modified from the Philosopher’s Stone to the Sorcerer’s Stone.
Some other examples include:
UK v. US
holiday - vacation
skip - dumpster
sherbet lemon - lemon drop
crisps - chips
soccer - football
Grammar
Although speakers of both variants are able to understand each other, there are significant differences between them in terms of grammar, from prepositions (at, in, to, etc.) to tenses.
UK v. US
Writing to someone - writing someone
In hospital - in the hospital
I have already eaten - I already ate
Monday to Friday - Monday through Friday
Even seemingly minor changes to punctuation and date conventions can make all the difference in addressing a new target audience. The same can be said of different areas of the world which have the same ‘official’ language, such as mainland Spain and Latin America, or France and Canada. You must make sure to speak directly to your target audience in order for them to be fully engaged by your material.