What is the Lido stETH fee?

Could you please clarify what the Lido stETH fee represents? I'm curious about how this fee is calculated and what factors determine its amount. Additionally, I'd like to know if there are any specific conditions or circumstances that might affect the fee. Is it a fixed amount or does it vary based on the transaction size or other factors? Finally, I'm interested in understanding how this fee compares to other similar services or platforms in the cryptocurrency space. Thank you for your assistance.