The Source Code is human readable but machines can’t understand instructions given in English, or any other human language, directly so this code is actually of no use to the machine until compiled by the compiler of the language into machine executable code. This file is written following some conventions and rules of a particular programming language that can be any high level language of programmer’s choice and is saved accordingly with the correct extension. For Example – ‘.java’ for JAVA code, ‘.cs’ for C# code, etc. The programmer writes the code for performing some task in the human readable language, almost English every time, and saves the file into a prescribed format. Source Code refers to file which is a text based document that is written by the programmer.
The line above is sufficient if you are looking for a definition of the Source Code, adding to this, the following points will help in a better understanding of the topic. Source Code, as the name suggests, it is the source of a program, the file original which is written by the programmer.
Here you will learn about difference between source code and object code.