This will vary from distribution to distribution. In most KDE distros, you can press Alt-F2, and then enter "konsole." In most distros that use GNOME, you can press Alt-F2 and enter "gnome-terminal".
Most programs in Linux are written using C or C++.
C is a programming language. A shell is an interface.
C programming is just that no matter if the operating system is Windows or Linux. Operating systems usually have an Application Program Interface that is commonly known as an API. The APIs of Windows will be different than Linux because the operating systems are (very) different.
It is a Linux-based open source operating system. Programming languages are in C, C++, and Java, with apps being written in a customized version of Java.
Linux supports any written language: it understands Unicode natively, so it can display the characters of any language with the appropriate locales included. As far as programming languages, Linux is written in C, but almost any language, from assembly to C to C++ to Python to Perl to .NET can be used on it.
C, C++ and scripts in Bash, Perl and Python
There is very little difference in the C compiler between Unix and Linux; in some cases (the gcc compiler) it is the same. The differences come in when using system calls; some system calls do not exist in Unix or Linux, although most do. The program I work on compiles the same way (for the most part) between all commercial versions of Unix and several variants of Linux. In other words, the code is fairly portable across platforms.
C isn't a program, or something you install; it is a programming language for writing software. Linux and most of the programs that run on it were written in C, and a C compiler and libraries are supplied with most systems, or are readily available.
Linux is a platform, and as such supports a myriad of programming languages. Of these languages C, C++, Java, Python and Perl are very popular, but there are many other programming languages. Some, like Python and Perl are 'interpretive' and similar in this respect to 'BASIC'. C and C++ are compiled, and Java sits somewhere between them.
There is a 'getch' in 'conio.h' which has nothing to do with 'iostream'.
C++ has nothing to do with pixels. Your question may be related with 'Windows programming' or 'DOS programming' or 'X Window System programming'.
Linux supports virtually all programming languages, both compiled and interpreted, commonplace and esoteric. It would be impossible to list all of them, but a comprehensive list can be found below:Compiled languagesCC++C# (through the Mono and DotGNU projects)Assembly (multiple CPUs)Objective-CFortranPascalDHaskellInterpreted languagesBashBasic (several dialects)MATLABPerlPHPPythonRubySmalltalk