Difference between celestial brew and celestial infusion?

i don’t see the difference ? can someone tell me please

One is a flat out shield against the damage, when it runs out it runs out. the other works more like a Prot warriors Ignore Pain in that it reduces incoming damage by 30%, this spreading out the damage even more and prevents bigger hits from nuking you down.

So it really comes down to an up front bubble or a spreading out of damage over time.

doesnt take long for 1.4 mil to run out …
so about the same thing yes?

The amount is the same but spread out. Infusion therefore is going to smooth damage out more if you are getting lots of little hits over a prolonged period while brew will be more bursty - completely no damage vs full damage taken. In general infusion is going to be the go in m+ while brew will be more for raid/tank busters. In low end content brew probably will be good too because you won’t even consume the whole shield over the duration.