What is 'source code' in the context of programming?

Source code refers to the human-readable set of instructions and statements written by a programmer using a specific programming language. This code expresses the logic and operations that the program should execute. It serves as the foundation for software development, allowing developers to create, modify, and understand the functionality of their applications.

When programmers write source code, they use symbols, keywords, and rules specific to the programming language, enabling them to communicate complex algorithms and operations in a manner that other developers can easily read and maintain. This source code is then translated into machine language by a compiler or interpreter, enabling the computer to execute the instructions.

The other concepts mentioned do not correctly represent source code: compiled machine language is processed code that the computer can execute, memory refers to data storage inside the computer, and the user interface is the graphical layout that users interact with, none of which reflect the essence of what source code is.