Commissions are amounts that are paid when trading cryptocurrencies (and with other types of blockchain tools, such as NFTs), and they are a daily concern for anyone dedicated to trading or for those who are constantly trying to optimize their token and cryptocurrency portfolios.
These amounts represent a payment for using a network or a crypto tool based on blockchain, and in general, they are allocated for its maintenance: in some cases, they cover the mining costs of the operations and in others, they represent a payment for the services offered by a platform, for example, an exchange. Keep in mind that these commissions help regulate two aspects of the crypto ecosystem. On one hand, having a cost for "doing things" on blockchain networks keeps the environment cleaner and more serious. On the other, it funds a transparent system for validating and recording transactions, known as mining.
However, each blockchain network chooses its protocol and mining system, and each has its own characteristics, from transaction delays and the number of security confirmations to the hardware needed to mine each network. Certain protocols are more costly than others.