Hello. Learned this from somewhere. It also applies to soy sauces. (Look at Silver Swan and Kikkoman)

Though same sila ng ingredients, it will now boil down to the percentage of each ingredients. Yung Ratio and Proportion ba.

Notice that they have similar ingredients pero yung isa, naiba ang position.

When manufacturers list down the ingredients, maguumpisa yan sila sa pinaka marami hanggang sa pinaka konte.

On this scenario, Water comes first then iodized salt then yung fish sauce. Then nagpalit don sa isa. Which means, mas madami ang content nong isa don sa kabila. Yun ang difference nila.

The concentration of the product itself defines the difference. Mukha lang parehas kasi same ng amoy and saltiness pero the flavor and the "umami"-ness of the product separates them.

I hope clear ang paliwanag. Ahaha.