Object and executable code in C Language
Source code is the C program that you write in your editor and save with a ‘ .C ‘ extension. Which is un-compiled (when written for the first time or whenever a change is made in it and saved).
Object code is the output of a compiler after it processes the source code. The object code is usually a machine code, also called a machine language, which can be understood directly by a specific type of CPU (central processing unit), such as x86 (i.e., Intel-compatible) or PowerPC. However, some compilers are designed to convert source code into an assembly language or some other another programming language. An assembly language is a human-readable notation using the mnemonics (mnemonicis a symbolic name for a single executable machine language instruction called an opcode) in the ISA ( Instruction Set Architecture) of that particular CPU .
Executable (also called the Binary) is the output of a linker after it processes the object code. A machine code file can be immediately executable (i.e., runnable as a program), or it might require linking with other object code files (e.g. libraries) to produce a complete executable program.