What is machine code?

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  • Post last modified:March 15, 2025

What is machine code?

  • A low-level programming language consisting of binary digits/bits that the computer reads and understands
  • A high-level programming language consisting of instruction lists that human can read and understands
  • A medium-level programming language consisting of the assembly code designed for the computer processor
  • A low-level programming language consisting of hexadecimal digits that make up high-level language instructions

The correct answer is:

A low-level programming language consisting of binary digits/bits that the computer reads and understands.

Explanation:

What is Machine Code?

Machine code is the lowest level of programming language that is directly executed by a computer’s processor. It consists of binary digits (0s and 1s) that represent instructions and data. Machine code is specific to the architecture of the processor, meaning it varies between different types of CPUs.

Characteristics of Machine Code:

  1. Binary Representation:
    • Instructions and data are encoded in binary format because computers operate using electrical signals that represent two states: ON (1) and OFF (0).
    • Example: 11001010 10101000 might represent a simple operation like adding two numbers.
  2. Processor-Specific:
    • Each processor has its own instruction set architecture (ISA), which defines the machine code instructions it can understand (e.g., x86, ARM, MIPS).
    • This means machine code for one type of processor cannot usually run on another.
  3. Hard for Humans to Read:
    • Unlike high-level or even assembly languages, machine code is almost impossible for humans to read or write directly.
    • Programmers use higher-level languages that are compiled or interpreted into machine code.
  4. Direct Execution:
    • Machine code is the only type of code a computer’s CPU can execute without further translation.

Why the Other Options are Incorrect:

  1. “A high-level programming language consisting of instruction lists that humans can read and understand”:
    • This describes a high-level language like Python, Java, or C++. These languages are designed to be human-readable and must be translated into machine code (via a compiler or interpreter) for the CPU to execute.
  2. “A medium-level programming language consisting of the assembly code designed for the computer processor”:
    • This describes assembly language, which is one step above machine code. Assembly language uses human-readable mnemonics (e.g., ADD, MOV) that correspond to machine code instructions. Assembly code must be assembled into machine code for execution.
  3. “A low-level programming language consisting of hexadecimal digits that make up high-level language instructions”:
    • Machine code can sometimes be represented in hexadecimal for easier reading (e.g., 3E A9 2B), but hexadecimal is not the machine code itself. It’s just a shorthand notation for binary.
    • Machine code doesn’t directly “make up high-level language instructions”; instead, high-level language instructions are translated into machine code.

Conclusion:

Machine code is a low-level programming language made up of binary digits (0s and 1s) that the computer’s processor can read and execute directly. It forms the foundation of all computing operations and serves as the final output of compilers or assemblers translating higher-level code.