I am using 34 size bra, bit confused with A, B and C size bra

I am using 34 size bra, bit confused with A, B and C size bra guide me which size will be bigger in B, C and D? - Quora

What is the difference between 32C and 34B bra sizes? - Quora

How to Determine Bra Size, Bra Fitting

How to Measure Your Bra Size the Right Way

17 Types of Bras: Cups, Straps, Support, Sizing, and More

34F Bras: Understanding the Cup Size Equivalents and Where to Shop - HauteFlair

Why You Can't Equate Bra Band Sizes With Dress Sizes

If bras are so ill-fitting, why isn't there a photographic and computer method to measure bust and chest dimensions to get the 'perfect fitting' bra? - Quora

Would a 32B bra fit the same as a 34A? - Quora

Is a 36D bra a medium or large bra? - Quora

Finally, Bra Sizes Explained – Understanding How Bra And Cup Sizes Work – ThirdLove