01
What is actually different
The processing, the water content and what you can verify with your own eyes.
Gel is dried sea moss that has been rinsed, soaked until it swells and softens, and blended with water. It is mostly water by weight, which is why a jar looks like a lot and a serving is a spoonful. It is a cold-chain food: it goes in the fridge and it has a finite life once opened.
Capsules start from the same dried material, which is then milled into powder and packed into shells. Taking the water out is what makes them shelf-stable, pocketable and tasteless. It is also what makes them impossible to inspect: a powder inside an opaque shell is a thing you have to take on trust.
Neither format adds anything to the sea moss. The differences are water, temperature and how much you can see.