There are numerous cards in Clash Royale. They are divided by many categories.They are divided by their rarity ,so according to that division, the cards can be: Common, Rare, Epic and Legendary.
According to the type, and the main characteristics, the cards can be divided into :Troop Cards, Building Cards and Spell Cards.
According to the targets, there are: Cards that target ground troops, Cards that target air troops,cards that target both air and ground troops and Cards that target buildings.
The Cards can be divided by the speed, so there are :slow Cards, Cards with medium speed, fast Cards and very fast Cards.
According to the Elixir cost, there are Cards with low Elixir cost, Cards with medium and Cards with high Elixir cost. The cheapest Card in Clash Rotyale costs 1 Elixir and the most expensive Card costs 9 Elixir.
We can go on with the categories of Cards, but you must remember that each Card in Clash Royale has its own purpose and mission, so combined together in a deck of 8 Cards, they can do miracles:).
We divided the Cars according to their rarity: