SourceCode is a collective noun refering to any human readable program which can be compiled or interpreted by a computer.

"Human readable" is a somewhat vague term, commonly referring to how easily a human can understand the code. On one end of the spectrum, many modern compilers translate their input language into intermediate C SourceCode that is very hard to follow despite being written in a high level language. On the other end, there are also humans who read and write AssemblyLanguage or even MachineCode.