Localisation is using a particular regional language variant so that your copy resonates with a specific audience and, just as important, is useful to them. Examples could be a cookbook or a website.
While all translations involve some localisation (in plain terms, adaptation), some, cookbooks being an example, require considerable adaptation and/or contextualisation; in my example, measures, some ingredients, oven temperatures and vocabulary.
The measures, oven temperatures and food vocabulary used by Spanish speakers in the USA will be totally different to those used by speakers in Spain. Likewise, food terminology varies immensely between the UK and the US and convention ovens are a lot more popular in the UK than in the US. Therefore, merely translating would not work. A non-specialist would not know how and when to adapt all these things and might not even know they need adapting.
With a website, for example, your British sense of humour might not work with the Spanish reader and your British references might not be relevant to them or, otherwise, might need contextualising.
How much does it cost?
Localisation services are charged per word or project and rates reflect the extra knowledge and translation time required. For example, cookbooks, recipes and menus often involve a great deal of research, even for a specialist, and attention to detail (lots of figures and symbols, you don’t want to omit an ingredient, etc.), which considerably slows down the translation process compared to more general texts.
I hired Pili to translate some pages of my website into Spanish because I was looking for a creative translator that would work with me to achieve a great result. Pili proved to be an extraordinarily detail-oriented translator. She cares about getting every aspect of your translation right and she’ll leave no stone unturned until you’re happy with the terminology choices, style and tone. I cannot recommend her highly enough and she will be my go-to translator for future projects of this kind.