Imagine being responsible for some of humanity's greatest achievements - perhaps even its very evolution - and yet only being known to most of earth's population because some people find you hard to stomach. This has long been the fate of gluten: the widely derided miracle worker behind many, if not most, of the world's greatest culinary hits.
Actually, let me rephrase that... miracle workers. Gluten is basically just the celebrity couple name for two specific classes of proteins found in some types of grasses: glutelins and prolamins. Glutelins are super flexible spring-like structures that just like to team up with each other to make long, stretchy coils. Prolamins are the more rigid part of the equation that keep the glutelins in line and bind them together to fix everything in place.
When you combine these wheat-derived wonder twins with water, they'll begin to link up and flex their combined muscle leaving you with a dense rubbery mass of pure gluten. Now, there are a lot of great ways to consume gluten hail seitan, but add a little starch to the equation and you get something a bit more versatile...
Dough. Or batter, if you really soak it. That's kinda up to you. I'm not your dad.
Beyond hydration, just about anything you change about your mix - the amount of starch, salinity, sugar, fat, pH balance, kneading, whipping, even if you just let your mix sit for a while - each of these will affect your final gluten structure.
These tests dig into just three factors, but they're perhaps the three most important factors to gluten development: hydration, protein, and time.