Do you pay for currency exchange?

I'm curious to know, when dealing with cryptocurrency transactions, is there a fee associated with converting one type of digital currency into another? Do I need to pay for this currency exchange process, and if so, what factors might influence the amount of that fee? Is there a standard rate across the industry, or does it vary based on the exchange platform or the specific cryptocurrencies involved? As a cryptocurrency user, I want to make sure I understand all the costs associated with my transactions, so I can make informed decisions about how and where to exchange my digital assets.