What is the merchant fee for Stripe?

Could you please clarify for me what the merchant fee is for Stripe? I'm interested in understanding the costs associated with using their payment processing services, and I'd like to get a clear idea of how much I can expect to pay for each transaction. Is the fee a flat rate, or does it vary based on the transaction amount or other factors? And are there any additional fees or charges that I should be aware of when using Stripe? Thank you for your help in clarifying this for me.