Initially, we must understand that any currency we want to buy will be against USDT, which is a stablecoin equivalent to the value of the dollar. This means that 1 USDT equals 1 dollar. In order to buy the currency, you need to have an account on a trading platform, such as Binance #Binance , which requires identity verification.
These are considered centralized platforms (there are decentralized platforms, and I will explain the difference between the two types later).
You can buy USDT from any broker available in your area, and its price is slightly lower than the actual dollar, and the price varies from one broker to another.