Video of reality weaver playing with some gems
SOUL
Soul is the source of magic found everywhere in the world, the energy allowing the user to cast magic. Terms that sound similar, but are vastly different in nature are “soul“ and “soul capacity“. It's important to differentiate the two.
Soul capacity is a set amount of soul each magical being can store within their body. This amount is unique for each individual and immutable, unless in special cases. It's the container that energy passes right through, soul getting used up and refilled as the magic is cast. Soul refills by itself over time in most cases, only sometimes requiring special rituals.
Soul is the resource that fills the soul capacity. It gets used up from the capacity when its owner uses magic, transforming in type to best suit the needed spell or action. Soul exists in most places in the world in higher or lower concentrations and cycles around like any other type of energy.
So far, soul hasn't been studied extensively and people's understanding of it is still very limited, but there are many active research teams working on it. The main agreed-upon concept is the one of touch and gate, touch being the type of soul and gate being the source of it.
TOUCH
Touch is the type of soul. It's used to describe the type of specific magic.
There are many types of soul that change from one to another while casting magic. Different touches are the names used to describe different soul types.
Since magic is the default, the word “touched“ means something is considered magical within the world as well. It's mostly used when something is magical in a specific way or possesses a rare type of soul.
A good example of this is touched beasts. Their normal counterparts usually use magic as well, but as this type of magic is the default for the species, so it's not considered “touched“. When the beast starts using different magic or is exposed to a different type of soul, only then is it considered “touched“.
GATE
Gates are different locations with high concentrations of soul all around the world. They're used to describe the origin of specific magic.
Many people believe that gates are a sole source of soul, creating it or bringing it from somewhere. It's widely believed that there would be no soul without them and by extension no magic. That's why gates are usually defended, protected, or worshipped by communities living around them.
However, certain locations of most gates remain unknown. Gates aren't used in any special way because they're not studied enough. Instead, they are used for refilling soul capacities of magical beings, like any other place rich in soul.