Noodles from different cuisines look broadly similar and behave nothing alike. The differences come from three decisions made before any water is boiled: the flour, the liquid and the method of forming.
The flour sets the ceiling
Wheat flours differ in protein content, and protein is what forms the gluten network responsible for elasticity and chew.
High-protein flour makes a dough that can be stretched thin without tearing, which is why pulled noodles require a strong flour and cannot be made from a soft one.
Noodles made from rice, buckwheat or mung bean starch have no gluten at all, so their structure comes from gelatinised starch and they behave more brittle and less springy.
What goes into the water changes the protein
Alkaline salts added to noodle dough raise its pH, which tightens the gluten network and turns the noodle firmer, yellower and distinctly springy.
That single addition is the main difference between an alkaline wheat noodle and an otherwise identical one made with plain water.
Salt, by contrast, strengthens gluten more gently and slows fermentation, which is why salted doughs can be rested longer before they are formed.
Forming method leaves a signature
Rolled and cut noodles have square edges and a uniform thickness, so they cook evenly and hold sauce along flat faces.
Pulled noodles are stretched by hand, giving slightly irregular cross-sections and a surface that has been worked rather than sliced, which changes how they grip liquid.
Extruded noodles are forced through a die under pressure, which compresses the dough and produces the dense, resilient texture typical of dried pasta shapes.
Drying is a separate product decision
Fresh noodles retain water, cook in a minute or two and have a soft, yielding bite that suits being eaten immediately.
Drying removes that water slowly enough to avoid cracking, and the resulting noodle takes far longer to cook and finishes firmer.
The two are not the same food in different states. Recipes calibrated for one give the wrong timing and the wrong texture with the other.
The broth was designed for the noodle
A noodle sitting in hot liquid keeps absorbing it, so noodles intended for soup are made firmer than those intended to be sauced and eaten dry.
Alkaline noodles resist softening particularly well, which is part of why they became standard in soups served very hot.
Swapping noodles between dishes therefore changes the timing of the whole bowl, not merely the texture of one component in it.