Is it free to send USDT?

I'm quite new to the realm of cryptocurrency and I'm still trying to wrap my head around all the intricacies. So, I have a question that might sound elementary to you experts, but I'm genuinely curious about it. Is it free to send USDT? I've heard that some cryptocurrencies have transaction fees, but I'm not sure if that applies to USDT as well. Could you please clarify this for me? It would be really helpful if you could also explain what factors, if any, might affect the cost of sending USDT. Thank you in advance for your time and assistance.