1. Mana
Mana is very important to Mages, Mana is strictly required to cast a spell, or else, you'll die. Mana is also tied to their life, examples, a Mage unconsciously cast too many spell at consecutive calls. The source of the casting is their hands, their hands will become limps and they cannot cast anymore spell until their hands recovered. And if they waste their Mana worse, they're digging on their own grave.
2. Magic
Magic is a common things in this story, their power meter is different on each user. Magic divides to 3 types, offensive, defense, and support. They all have their own ranks examples, S rank, A rank, B rank, and the lowest, D rank.
3. Spell
Spell is the thing Mages casts with their Mana. A lot Mages names their Spells, heavy Spell required chants and big amount of Mana in order to cast it, while light Spell doesn't need chants and big amount of Mana, just small, in order to cast it the caster just need to read it names. Though, the damages is obviously different.
4. Custom Spell/Card
Non-Mages first create this kind of things to help with their daily life, as peoples began to expand their capability. Creating offensive types of card and inserting their spells in the card, how to use it? Simple, read the chants or the name of the card, or just slam it down the floor to get it easily done.
5. Teleportation Spell
Teleportation Spell is a handy spell, many Mages use it to easily travel around the world. But it flaws is that, price are way too high, consume high amount of Mana if you teleport to hundreds of kilometers and it'll consume the user life slowly, due to the overload of teleporting. A lot of tragedy happened when Teleportation Spell was legally approved by the 5 Kingdom. And because of the sudden raise of victim because of Teleportation Spell, the 5 Kingdom then agreed to stop all marketing of Teleportation Spell, but of course, there will be someone who illegally sell them to citizens.