What Is The Difference Between Utf-8 And Utf-8-sig?

I am trying to encode Bangla words in python using pandas dataframe. But as encoding type, utf-8 is not working but utf-8-sig is. I know utf-8-sig is with BOM(Byte order mark). But

Solution 1:

"sig" in "utf-8-sig" is the abbreviation of "signature" (i.e. signature utf-8 file). Using utf-8-sig to read a file will treat BOM as file info. instead of a string.