Salt is for control.
It seasons without changing colour or flavour, so it’s great for marinades, velveting meat, and early seasoning when you don’t want the dish to taste like soy sauce.
Soy sauce is seasoning and flavour.
It adds saltiness, depth, umami, and colour. Use it when you want that classic Chinese savoury profile, especially in stir-fries and sauces.
The key difference?
Salt seasons quietly.
Soy sauce speaks up.
Knowing when to use each is what stops food tasting flat or overly soy-heavy.