Translation
Many visa, residence, and citizenship applications will require vital records (e.g. birth certificates), and background checks, etc. come with a translation into one of the country's official language.
Some documents may be required to be sworn translations or certified translations.[1] It's important to be aware that if the country (e.g. Spain) requires sworn translations, a certified translation will not be accepted.
Sworn Translations
Sworn translations are performed by translators who are recognized by the country's consulate. They are legally binding documents. The translations will be stamped with an official stamp unique to the sworn translator.
Many consulates will provide contact lists of sworn translators.
Certified Translations
A translation agency or individual can include a statement that certifies their translation is correct, and thus be a certified translation. Sometimes these will be notarized, but again, will not be accepted when a sworn translation is required.
When to Get Translations
If a document needs to be Apostilled, you need to have it apostilled first, then translated.
Otherwise, any other document can be translated as needed before application submission.