What C# means?

Answer 1

C# (pronounced as "C-sharp") is an
object-oriented programming language from Microsoft that aims to combine the computing power of C++ !!

Answer 2

In addition to Al Araf.

c- sharp is c ++
++

So it is a extension of c++ and is much more.
Having four plusses was to much so they choose the music sharp sign which is just one character.

https://en.wikipedia.org/wiki/C_Sharp_(programming_language)