Fiat currencies are the money we actually use, Euro, USD and so on. It is the largest market, with a daily total transaction amount $ 5 trillion. If you exchanged one currency for the currency of the place you went for your vacations, you were part of a Forex transaction.
The supply is decided by the central banks and there are third parties in the middle like commercial banks, which take fees and charges for people money transactions.

Fiat Money Categories

Major Currency Pairs- Major currency pairs are named this way since they contain the US Dollar and are the most traded FX pairs. Minor Currency Pairs- Minors are pairs that do not include the USD.
Exotic currency pairs- Currencies from developing economies coming in pair with a major currency. 

A crypto coin is a virtual currency designed to serve as a medium of exchange to make the transactions secure and safe.

Bitcoin is the main and first cryptocurrency out there. It is created to make peoples life easier and to cut the cost from third parties. Each time we make a bank transfer or transaction banks are keeping their interest, charging people unfairly. Nowadays system is called like a slavery economic system, Bitcoin is trying to transfer the power on the people hands and take it from banks and governments. This is the reason why these two parties are so against Bitcoin and other cryptos. Cryptocurrencies will make them powerless.

Who rules Crypto World?

Users, they might be an individual or a legal entity who obtains coins to purchase real or virtual goods or services.

Miners, they make the transactions valid by solving a ‘cryptographic puzzle’. They support the network by using computing power to validate transactions and are rewarded with new coins. They rise the supply.

Exchanges, they help cryptocurrency holders to convert their cryptos in fiat currencies and vise-versa.
Trading platforms are marketplaces that bring together different cryptocurrency users that are either looking to buy or sell coins, providing them with a platform on which they can directly trade with each other.
E- wallets are used to hold, store and transfer digital coins among the crypto users.