Pascal is an imperative programming language that is for the most part dead these days. It was very popular durin mid 70s through late 80s. There are many, many other languages out there. C, C++ and java are not the only programming languages. The number is big. Delphi, Clipper, Simula, Smalltak, Python, Visual Basic, Assembly, ....
C# is not C. Neither it is C++. C# is it's own programming language which borrows the syntax from C++. It only compiles and runs on computers with the .Net Runtime. It is thus a very limited language in terms of those who can benefit from its programs. It's just a YAPL (Yet Another Programming Language)