A source code is a body of text, consisting of characters which are instructions of a high-level programming language, written by a programmer and saved as a file.
A source code when tested is run by a compiler, translator or interpreter to convert it into machine code, which can be understood by a computer, for further display as a result.
For programming languages with the exception of JavaScript, a source code is converted to an object code with the aid of translators. JavaScript on the other end, has only form of code.
Mode of Working
A programmer typically types up a set of commands of a programming language through a text editor, or an integrated development environment (IDE), saves it, and test runs it with a translator.
The resulting object code, is then linked to library files and objects, to give a final executable file.
Licensing
Source code can be either open or proprietary. This depends on the licensing agreements governing the scenario.
Importance of Source Code
Source code plays a pivotal role in helping would-be programmers, and enthusiasts in improving their learning curve. A source code gives a first-hand view of how the structure of a programming language is, which makes learning easier for newbies.
A source code which is open source, can be reused for other software projects, and for educative purposes as well.