What is machine code?

Machine code is a set of instructions that are directly executed by a computer's processor. It is represented as binary numbers (zeros and ones), which the processor interprets as commands to perform operations such as arithmetic, logic, flow control, and memory access.

Each processor architecture has its own set of machine instructions, so machine code depends on the processor type. Programmers usually do not write machine code directly but use high-level programming languages or assembly, which are then compiled or translated into machine code.

Example: a processor instruction might look like a sequence of bytes, for example, 10110000 01100001 — this is machine code for a command to load a value into a register (on x86 architecture).