What is optimal equilvalence? I know the NIV used dynamic equivalence. So the question is what is the difference between the two?

Here is an extract from the opening paragraph on the website.
Quote
HOW THE CSB WAS TRANSLATED

The CSB was translated using a methodology called Optimal Equivalence, which balances contemporary English readability with linguistic precision to the original languages. In the many places throughout Scripture where a word-for-word rendering is clearly understandable, a literal translation is used. When a word-for-word rendering might obscure the meaning for a modern audience, a more dynamic translation is used.


John Chaney

"having been firmly rooted and now being built up in Him and established in your faith . . ." Colossians 2:7