Proofreading and Revising

It is well-established, best practice for a translation to be proofread
before being issued or published in its final form - even the most expert translator can (and does) make small mistakes. Obviously, if the translation has been produced by a less experienced translator, or possibly it has been produced in a hurry (it happens!), mistakes in the translation are inevitable.

Proofreading 

This is a standard service to ensure that the spelling and grammar in the French text is correct and consistent throughout.

However, proofreading is not only concerned with spelling mistakes; it is also about ensuring that the text conforms to French conventions in matters of, for example:
use of capital letterswriting numerals (e.g. the comma used as a decimal point)use of punctuation (including spacing)use of acronyms

Only the French text, translation or text written by a non-native, is needed for this service.

Revising

This is a more in-depth translation service to ensure that the French text accurately conveys the meaning, style and 'atmosphere' of the original English text. In other words, the aim is to ensure that the text reads like French, not translated English!

Revising the translation ensures that it is:
adapted for its intended purposetailored to its target audienceemploys the accurate and relevant terminologyuses appropriate cultural references

Revising implies the comparison of the English text to its French translation.