Which of one from string interpolation and string.format is better in performance?

Which of one from string interpolation and string.format is better in performance?

Neither of them is better since they are equal on run-time. String interpolation is rewritten by the compiler to string.Format, so both statements are exactly the same on run-time.

Also what are the best fit scenarios for use of them?

Use string interpolation if you have variables in scope which you want to use in your string formatting. String interpolation is safer since it has compile time checks on the validness of your string. Use string.Format if you load the text from an external source, like a resource file or database.